diff --git a/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/RemoteCommunication.cs b/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/RemoteCommunication.cs
index af2d57ff0..537ed5285 100644
--- a/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/RemoteCommunication.cs
+++ b/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/RemoteCommunication.cs
@@ -1164,7 +1164,7 @@ internal sealed class RemoteCommunication : IAsyncDisposable, IDisposable {
 		}
 	}
 
-	private async Task<bool> MatchActively(IReadOnlyCollection<ListedUser> listedUsers, IReadOnlyCollection<Asset> ourAssets, IReadOnlyCollection<EAssetType> acceptedMatchableTypes) {
+	private async Task<bool> MatchActively(ImmutableHashSet<ListedUser> listedUsers, HashSet<Asset> ourAssets, HashSet<EAssetType> acceptedMatchableTypes) {
 		if ((listedUsers == null) || (listedUsers.Count == 0)) {
 			throw new ArgumentNullException(nameof(listedUsers));
 		}
diff --git a/ArchiSteamFarm.Tests/AssemblyInfo.cs b/ArchiSteamFarm.Tests/AssemblyInfo.cs
index f432632cb..3075a7cd8 100644
--- a/ArchiSteamFarm.Tests/AssemblyInfo.cs
+++ b/ArchiSteamFarm.Tests/AssemblyInfo.cs
@@ -25,4 +25,5 @@ using System;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
 [assembly: CLSCompliant(false)]
+[assembly: DiscoverInternals]
 [assembly: Parallelize(Scope = ExecutionScope.MethodLevel)]
diff --git a/ArchiSteamFarm.Tests/Bot.cs b/ArchiSteamFarm.Tests/Bot.cs
index 640c24bca..8c3d0ccc6 100644
--- a/ArchiSteamFarm.Tests/Bot.cs
+++ b/ArchiSteamFarm.Tests/Bot.cs
@@ -23,6 +23,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using ArchiSteamFarm.Steam.Data;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
@@ -30,10 +31,11 @@ using static ArchiSteamFarm.Steam.Bot;
 
 namespace ArchiSteamFarm.Tests;
 
+#pragma warning disable CA1812 // False positive, the class is used during MSTest
 [TestClass]
-public sealed class Bot {
+internal sealed class Bot {
 	[TestMethod]
-	public void MaxItemsBarelyEnoughForOneSet() {
+	internal void MaxItemsBarelyEnoughForOneSet() {
 		const uint relevantAppID = 42;
 
 		Dictionary<uint, byte> itemsPerSet = new() {
@@ -57,7 +59,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void MaxItemsTooSmall() {
+	internal void MaxItemsTooSmall() {
 		const uint appID = 42;
 
 		HashSet<Asset> items = [
@@ -69,7 +71,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void MoreCardsThanNeeded() {
+	internal void MoreCardsThanNeeded() {
 		const uint appID = 42;
 
 		HashSet<Asset> items = [
@@ -91,7 +93,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void MultipleSets() {
+	internal void MultipleSets() {
 		const uint appID = 42;
 
 		HashSet<Asset> items = [
@@ -112,7 +114,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void MultipleSetsDifferentAmount() {
+	internal void MultipleSetsDifferentAmount() {
 		const uint appID = 42;
 
 		HashSet<Asset> items = [
@@ -132,7 +134,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void MutliRarityAndType() {
+	internal void MutliRarityAndType() {
 		const uint appID = 42;
 
 		HashSet<Asset> items = [
@@ -173,7 +175,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void NotAllCardsPresent() {
+	internal void NotAllCardsPresent() {
 		const uint appID = 42;
 
 		HashSet<Asset> items = [
@@ -188,7 +190,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void OneSet() {
+	internal void OneSet() {
 		const uint appID = 42;
 
 		HashSet<Asset> items = [
@@ -207,7 +209,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void OtherAppIDFullSets() {
+	internal void OtherAppIDFullSets() {
 		const uint appID0 = 42;
 		const uint appID1 = 43;
 
@@ -232,7 +234,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void OtherAppIDNoSets() {
+	internal void OtherAppIDNoSets() {
 		const uint appID0 = 42;
 		const uint appID1 = 43;
 
@@ -254,7 +256,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void OtherAppIDOneSet() {
+	internal void OtherAppIDOneSet() {
 		const uint appID0 = 42;
 		const uint appID1 = 43;
 		const uint appID2 = 44;
@@ -286,7 +288,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void OtherRarityFullSets() {
+	internal void OtherRarityFullSets() {
 		const uint appID = 42;
 
 		HashSet<Asset> items = [
@@ -304,7 +306,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void OtherRarityNoSets() {
+	internal void OtherRarityNoSets() {
 		const uint appID = 42;
 
 		HashSet<Asset> items = [
@@ -320,7 +322,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void OtherRarityOneSet() {
+	internal void OtherRarityOneSet() {
 		const uint appID = 42;
 
 		HashSet<Asset> items = [
@@ -343,7 +345,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void OtherTypeFullSets() {
+	internal void OtherTypeFullSets() {
 		const uint appID = 42;
 
 		HashSet<Asset> items = [
@@ -361,7 +363,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void OtherTypeNoSets() {
+	internal void OtherTypeNoSets() {
 		const uint appID = 42;
 
 		HashSet<Asset> items = [
@@ -377,7 +379,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void OtherTypeOneSet() {
+	internal void OtherTypeOneSet() {
 		const uint appID = 42;
 
 		HashSet<Asset> items = [
@@ -400,7 +402,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void TooHighAmount() {
+	internal void TooHighAmount() {
 		const uint appID0 = 42;
 
 		HashSet<Asset> items = [
@@ -419,7 +421,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void TooManyCardsForSingleTrade() {
+	internal void TooManyCardsForSingleTrade() {
 		const uint appID = 42;
 
 		HashSet<Asset> items = [];
@@ -435,7 +437,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void TooManyCardsForSingleTradeMultipleAppIDs() {
+	internal void TooManyCardsForSingleTradeMultipleAppIDs() {
 		const uint appID0 = 42;
 		const uint appID1 = 43;
 
@@ -459,7 +461,7 @@ public sealed class Bot {
 	}
 
 	[TestMethod]
-	public void TooManyCardsPerSet() {
+	internal void TooManyCardsPerSet() {
 		const uint appID0 = 42;
 		const uint appID1 = 43;
 		const uint appID2 = 44;
@@ -482,7 +484,7 @@ public sealed class Bot {
 		);
 	}
 
-	private static void AssertResultMatchesExpectation(IReadOnlyDictionary<(uint RealAppID, ulong ContextID, ulong ClassID), uint> expectedResult, IReadOnlyCollection<Asset> itemsToSend) {
+	private static void AssertResultMatchesExpectation(Dictionary<(uint RealAppID, ulong ContextID, ulong ClassID), uint> expectedResult, IReadOnlyCollection<Asset> itemsToSend) {
 		ArgumentNullException.ThrowIfNull(expectedResult);
 		ArgumentNullException.ThrowIfNull(itemsToSend);
 
@@ -495,9 +497,10 @@ public sealed class Bot {
 
 	private static HashSet<Asset> GetItemsForFullBadge(IReadOnlyCollection<Asset> inventory, byte cardsPerSet, uint appID, ushort maxItems = Steam.Exchange.Trading.MaxItemsPerTrade) => GetItemsForFullBadge(inventory, new Dictionary<uint, byte> { { appID, cardsPerSet } }, maxItems);
 
-	private static HashSet<Asset> GetItemsForFullBadge(IReadOnlyCollection<Asset> inventory, IDictionary<uint, byte> cardsPerSet, ushort maxItems = Steam.Exchange.Trading.MaxItemsPerTrade) {
+	private static HashSet<Asset> GetItemsForFullBadge(IReadOnlyCollection<Asset> inventory, [SuppressMessage("ReSharper", "SuggestBaseTypeForParameter")] Dictionary<uint, byte> cardsPerSet, ushort maxItems = Steam.Exchange.Trading.MaxItemsPerTrade) {
 		Dictionary<(uint RealAppID, EAssetType Type, EAssetRarity Rarity), List<uint>> inventorySets = Steam.Exchange.Trading.GetInventorySets(inventory);
 
 		return GetItemsForFullSets(inventory, inventorySets.ToDictionary(static kv => kv.Key, kv => (SetsToExtract: inventorySets[kv.Key][0], cardsPerSet[kv.Key.RealAppID])), maxItems).ToHashSet();
 	}
 }
+#pragma warning restore CA1812 // False positive, the class is used during MSTest
diff --git a/ArchiSteamFarm.Tests/SteamChatMessage.cs b/ArchiSteamFarm.Tests/SteamChatMessage.cs
index 1fe082a8f..307a0b789 100644
--- a/ArchiSteamFarm.Tests/SteamChatMessage.cs
+++ b/ArchiSteamFarm.Tests/SteamChatMessage.cs
@@ -31,10 +31,11 @@ using static ArchiSteamFarm.Steam.Integration.SteamChatMessage;
 
 namespace ArchiSteamFarm.Tests;
 
+#pragma warning disable CA1812 // False positive, the class is used during MSTest
 [TestClass]
-public sealed class SteamChatMessage {
+internal sealed class SteamChatMessage {
 	[TestMethod]
-	public async Task CanSplitEvenWithStupidlyLongPrefix() {
+	internal async Task CanSplitEvenWithStupidlyLongPrefix() {
 		string prefix = new('x', MaxMessagePrefixBytes);
 
 		const string emoji = "😎";
@@ -51,10 +52,10 @@ public sealed class SteamChatMessage {
 	}
 
 	[TestMethod]
-	public void ContinuationCharacterSizeIsProperlyCalculated() => Assert.AreEqual(ContinuationCharacterBytes, Encoding.UTF8.GetByteCount(ContinuationCharacter.ToString()));
+	internal void ContinuationCharacterSizeIsProperlyCalculated() => Assert.AreEqual(ContinuationCharacterBytes, Encoding.UTF8.GetByteCount(ContinuationCharacter.ToString()));
 
 	[TestMethod]
-	public async Task DoesntSkipEmptyNewlines() {
+	internal async Task DoesntSkipEmptyNewlines() {
 		string message = $"asdf{Environment.NewLine}{Environment.NewLine}asdf";
 
 		List<string> output = await GetMessageParts(message).ToListAsync().ConfigureAwait(false);
@@ -66,7 +67,7 @@ public sealed class SteamChatMessage {
 	[DataRow(false)]
 	[DataRow(true)]
 	[DataTestMethod]
-	public async Task DoesntSplitInTheMiddleOfMultiByteChar(bool isAccountLimited) {
+	internal async Task DoesntSplitInTheMiddleOfMultiByteChar(bool isAccountLimited) {
 		int maxMessageBytes = isAccountLimited ? MaxMessageBytesForLimitedAccounts : MaxMessageBytesForUnlimitedAccounts;
 		int longLineLength = maxMessageBytes - ReservedContinuationMessageBytes;
 
@@ -84,7 +85,7 @@ public sealed class SteamChatMessage {
 	}
 
 	[TestMethod]
-	public async Task DoesntSplitJustBecauseOfLastEscapableCharacter() {
+	internal async Task DoesntSplitJustBecauseOfLastEscapableCharacter() {
 		const string message = "abcdef[";
 		const string escapedMessage = @"abcdef\[";
 
@@ -97,7 +98,7 @@ public sealed class SteamChatMessage {
 	[DataRow(false)]
 	[DataRow(true)]
 	[DataTestMethod]
-	public async Task DoesntSplitOnBackslashNotUsedForEscaping(bool isAccountLimited) {
+	internal async Task DoesntSplitOnBackslashNotUsedForEscaping(bool isAccountLimited) {
 		int maxMessageBytes = isAccountLimited ? MaxMessageBytesForLimitedAccounts : MaxMessageBytesForUnlimitedAccounts;
 		int longLineLength = maxMessageBytes - ReservedContinuationMessageBytes;
 
@@ -113,7 +114,7 @@ public sealed class SteamChatMessage {
 	[DataRow(false)]
 	[DataRow(true)]
 	[DataTestMethod]
-	public async Task DoesntSplitOnEscapeCharacter(bool isAccountLimited) {
+	internal async Task DoesntSplitOnEscapeCharacter(bool isAccountLimited) {
 		int maxMessageBytes = isAccountLimited ? MaxMessageBytesForLimitedAccounts : MaxMessageBytesForUnlimitedAccounts;
 		int longLineLength = maxMessageBytes - ReservedContinuationMessageBytes;
 
@@ -129,7 +130,7 @@ public sealed class SteamChatMessage {
 	}
 
 	[TestMethod]
-	public async Task NoNeedForAnySplittingWithNewlines() {
+	internal async Task NoNeedForAnySplittingWithNewlines() {
 		string message = $"abcdef{Environment.NewLine}ghijkl{Environment.NewLine}mnopqr";
 
 		List<string> output = await GetMessageParts(message).ToListAsync().ConfigureAwait(false);
@@ -139,7 +140,7 @@ public sealed class SteamChatMessage {
 	}
 
 	[TestMethod]
-	public async Task NoNeedForAnySplittingWithoutNewlines() {
+	internal async Task NoNeedForAnySplittingWithoutNewlines() {
 		const string message = "abcdef";
 
 		List<string> output = await GetMessageParts(message).ToListAsync().ConfigureAwait(false);
@@ -149,10 +150,10 @@ public sealed class SteamChatMessage {
 	}
 
 	[TestMethod]
-	public void ParagraphCharacterSizeIsLessOrEqualToContinuationCharacterSize() => Assert.IsTrue(ContinuationCharacterBytes >= Encoding.UTF8.GetByteCount(ParagraphCharacter.ToString()));
+	internal void ParagraphCharacterSizeIsLessOrEqualToContinuationCharacterSize() => Assert.IsTrue(ContinuationCharacterBytes >= Encoding.UTF8.GetByteCount(ParagraphCharacter.ToString()));
 
 	[TestMethod]
-	public async Task ProperlyEscapesCharacters() {
+	internal async Task ProperlyEscapesCharacters() {
 		const string message = @"[b]bold[/b] \n";
 		const string escapedMessage = @"\[b]bold\[/b] \\n";
 
@@ -163,7 +164,7 @@ public sealed class SteamChatMessage {
 	}
 
 	[TestMethod]
-	public async Task ProperlyEscapesSteamMessagePrefix() {
+	internal async Task ProperlyEscapesSteamMessagePrefix() {
 		const string prefix = "/pre []";
 		const string escapedPrefix = @"/pre \[]";
 
@@ -178,7 +179,7 @@ public sealed class SteamChatMessage {
 	[DataRow(false)]
 	[DataRow(true)]
 	[DataTestMethod]
-	public async Task ProperlySplitsLongSingleLine(bool isAccountLimited) {
+	internal async Task ProperlySplitsLongSingleLine(bool isAccountLimited) {
 		int maxMessageBytes = isAccountLimited ? MaxMessageBytesForLimitedAccounts : MaxMessageBytesForUnlimitedAccounts;
 		int longLineLength = maxMessageBytes - ReservedContinuationMessageBytes;
 
@@ -196,10 +197,10 @@ public sealed class SteamChatMessage {
 	}
 
 	[TestMethod]
-	public void ReservedSizeForEscapingIsProperlyCalculated() => Assert.AreEqual(ReservedEscapeMessageBytes, Encoding.UTF8.GetByteCount(@"\") + 4); // Maximum amount of bytes per single UTF-8 character is 4, not 6 as from Encoding.UTF8.GetMaxByteCount(1)
+	internal void ReservedSizeForEscapingIsProperlyCalculated() => Assert.AreEqual(ReservedEscapeMessageBytes, Encoding.UTF8.GetByteCount(@"\") + 4); // Maximum amount of bytes per single UTF-8 character is 4, not 6 as from Encoding.UTF8.GetMaxByteCount(1)
 
 	[TestMethod]
-	public async Task RyzhehvostInitialTestForSplitting() {
+	internal async Task RyzhehvostInitialTestForSplitting() {
 		const string prefix = "/me ";
 
 		const string message = """
@@ -285,7 +286,7 @@ public sealed class SteamChatMessage {
 	[DataRow(false)]
 	[DataRow(true)]
 	[DataTestMethod]
-	public async Task SplitsOnNewlinesWithParagraphCharacter(bool isAccountLimited) {
+	internal async Task SplitsOnNewlinesWithParagraphCharacter(bool isAccountLimited) {
 		int maxMessageBytes = isAccountLimited ? MaxMessageBytesForLimitedAccounts : MaxMessageBytesForUnlimitedAccounts;
 
 		StringBuilder newlinePartBuilder = new();
@@ -314,7 +315,7 @@ public sealed class SteamChatMessage {
 	}
 
 	[TestMethod]
-	public async Task ThrowsOnTooLongNewlinesPrefix() {
+	internal async Task ThrowsOnTooLongNewlinesPrefix() {
 		string prefix = new('\n', (MaxMessagePrefixBytes / NewlineWeight) + 1);
 
 		const string message = "asdf";
@@ -323,7 +324,7 @@ public sealed class SteamChatMessage {
 	}
 
 	[TestMethod]
-	public async Task ThrowsOnTooLongPrefix() {
+	internal async Task ThrowsOnTooLongPrefix() {
 		string prefix = new('x', MaxMessagePrefixBytes + 1);
 
 		const string message = "asdf";
@@ -331,3 +332,4 @@ public sealed class SteamChatMessage {
 		await Assert.ThrowsExceptionAsync<ArgumentOutOfRangeException>(async () => await GetMessageParts(message, prefix).ToListAsync().ConfigureAwait(false)).ConfigureAwait(false);
 	}
 }
+#pragma warning restore CA1812 // False positive, the class is used during MSTest
diff --git a/ArchiSteamFarm.Tests/Trading.cs b/ArchiSteamFarm.Tests/Trading.cs
index ca2006c9c..2d074b00d 100644
--- a/ArchiSteamFarm.Tests/Trading.cs
+++ b/ArchiSteamFarm.Tests/Trading.cs
@@ -28,10 +28,11 @@ using static ArchiSteamFarm.Steam.Exchange.Trading;
 
 namespace ArchiSteamFarm.Tests;
 
+#pragma warning disable CA1812 // False positive, the class is used during MSTest
 [TestClass]
-public sealed class Trading {
+internal sealed class Trading {
 	[TestMethod]
-	public void ExploitingNewSetsIsFairButNotNeutral() {
+	internal void ExploitingNewSetsIsFairButNotNeutral() {
 		HashSet<Asset> inventory = [
 			CreateItem(1, amount: 40),
 			CreateItem(2, amount: 10),
@@ -53,7 +54,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void Issue3203() {
+	internal void Issue3203() {
 		HashSet<Asset> inventory = [
 			CreateItem(1, amount: 2),
 			CreateItem(2, amount: 6),
@@ -77,7 +78,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void MismatchRarityIsNotFair() {
+	internal void MismatchRarityIsNotFair() {
 		HashSet<Asset> itemsToGive = [
 			CreateItem(1, rarity: EAssetRarity.Rare)
 		];
@@ -90,7 +91,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void MismatchRealAppIDsIsNotFair() {
+	internal void MismatchRealAppIDsIsNotFair() {
 		HashSet<Asset> itemsToGive = [
 			CreateItem(1, realAppID: 570)
 		];
@@ -103,7 +104,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void MismatchTypesIsNotFair() {
+	internal void MismatchTypesIsNotFair() {
 		HashSet<Asset> itemsToGive = [
 			CreateItem(1, type: EAssetType.Emoticon)
 		];
@@ -116,7 +117,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void MultiGameMultiTypeBadReject() {
+	internal void MultiGameMultiTypeBadReject() {
 		HashSet<Asset> inventory = [
 			CreateItem(1, amount: 9),
 			CreateItem(3, amount: 9, realAppID: 730, type: EAssetType.Emoticon),
@@ -138,7 +139,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void MultiGameMultiTypeNeutralAccept() {
+	internal void MultiGameMultiTypeNeutralAccept() {
 		HashSet<Asset> inventory = [
 			CreateItem(1, amount: 9),
 			CreateItem(3, realAppID: 730, type: EAssetType.Emoticon)
@@ -159,7 +160,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void MultiGameSingleTypeBadReject() {
+	internal void MultiGameSingleTypeBadReject() {
 		HashSet<Asset> inventory = [
 			CreateItem(1, amount: 9),
 			CreateItem(3, realAppID: 730),
@@ -181,7 +182,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void MultiGameSingleTypeNeutralAccept() {
+	internal void MultiGameSingleTypeNeutralAccept() {
 		HashSet<Asset> inventory = [
 			CreateItem(1, amount: 2),
 			CreateItem(3, realAppID: 730)
@@ -202,7 +203,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void SingleGameAbrynosWasWrongNeutralAccept() {
+	internal void SingleGameAbrynosWasWrongNeutralAccept() {
 		HashSet<Asset> inventory = [
 			CreateItem(1),
 			CreateItem(2, amount: 2),
@@ -224,7 +225,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void SingleGameDonationAccept() {
+	internal void SingleGameDonationAccept() {
 		HashSet<Asset> inventory = [
 			CreateItem(1)
 		];
@@ -243,7 +244,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void SingleGameMultiTypeBadReject() {
+	internal void SingleGameMultiTypeBadReject() {
 		HashSet<Asset> inventory = [
 			CreateItem(1, amount: 9),
 			CreateItem(3, amount: 9, type: EAssetType.Emoticon),
@@ -265,7 +266,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void SingleGameMultiTypeNeutralAccept() {
+	internal void SingleGameMultiTypeNeutralAccept() {
 		HashSet<Asset> inventory = [
 			CreateItem(1, amount: 9),
 			CreateItem(3, type: EAssetType.Emoticon)
@@ -286,7 +287,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void SingleGameQuantityBadReject() {
+	internal void SingleGameQuantityBadReject() {
 		HashSet<Asset> inventory = [
 			CreateItem(1),
 			CreateItem(2),
@@ -308,7 +309,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void SingleGameQuantityBadReject2() {
+	internal void SingleGameQuantityBadReject2() {
 		HashSet<Asset> inventory = [
 			CreateItem(1),
 			CreateItem(2, amount: 2)
@@ -328,7 +329,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void SingleGameQuantityNeutralAccept() {
+	internal void SingleGameQuantityNeutralAccept() {
 		HashSet<Asset> inventory = [
 			CreateItem(1, amount: 2),
 			CreateItem(2)
@@ -348,7 +349,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void SingleGameSingleTypeBadReject() {
+	internal void SingleGameSingleTypeBadReject() {
 		HashSet<Asset> inventory = [
 			CreateItem(1),
 			CreateItem(2)
@@ -367,7 +368,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void SingleGameSingleTypeBadWithOverpayingReject() {
+	internal void SingleGameSingleTypeBadWithOverpayingReject() {
 		HashSet<Asset> inventory = [
 			CreateItem(1, amount: 2),
 			CreateItem(2, amount: 2),
@@ -388,7 +389,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void SingleGameSingleTypeBigDifferenceAccept() {
+	internal void SingleGameSingleTypeBigDifferenceAccept() {
 		HashSet<Asset> inventory = [
 			CreateItem(1),
 			CreateItem(2, amount: 5),
@@ -408,7 +409,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void SingleGameSingleTypeBigDifferenceReject() {
+	internal void SingleGameSingleTypeBigDifferenceReject() {
 		HashSet<Asset> inventory = [
 			CreateItem(1),
 			CreateItem(2, amount: 2),
@@ -432,7 +433,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void SingleGameSingleTypeGoodAccept() {
+	internal void SingleGameSingleTypeGoodAccept() {
 		HashSet<Asset> inventory = [
 			CreateItem(1, amount: 2)
 		];
@@ -450,7 +451,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void SingleGameSingleTypeNeutralAccept() {
+	internal void SingleGameSingleTypeNeutralAccept() {
 		HashSet<Asset> inventory = [
 			CreateItem(1)
 		];
@@ -468,7 +469,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void SingleGameSingleTypeNeutralWithOverpayingAccept() {
+	internal void SingleGameSingleTypeNeutralWithOverpayingAccept() {
 		HashSet<Asset> inventory = [
 			CreateItem(1, amount: 2),
 			CreateItem(2, amount: 2)
@@ -488,7 +489,7 @@ public sealed class Trading {
 	}
 
 	[TestMethod]
-	public void TakingExcessiveAmountOfSingleCardCanStillBeFairAndNeutral() {
+	internal void TakingExcessiveAmountOfSingleCardCanStillBeFairAndNeutral() {
 		HashSet<Asset> inventory = [
 			CreateItem(1, amount: 52),
 			CreateItem(2, amount: 73),
@@ -515,3 +516,4 @@ public sealed class Trading {
 
 	private static Asset CreateItem(ulong classID, ulong instanceID = 0, uint amount = 1, bool marketable = false, bool tradable = false, uint realAppID = Asset.SteamAppID, EAssetType type = EAssetType.TradingCard, EAssetRarity rarity = EAssetRarity.Common) => new(Asset.SteamAppID, Asset.SteamCommunityContextID, classID, amount, new InventoryDescription(Asset.SteamAppID, classID, instanceID, marketable, tradable, realAppID, type, rarity));
 }
+#pragma warning restore CA1812 // False positive, the class is used during MSTest
diff --git a/ArchiSteamFarm/Steam/Bot.cs b/ArchiSteamFarm/Steam/Bot.cs
index 921fc5b11..06092b951 100644
--- a/ArchiSteamFarm/Steam/Bot.cs
+++ b/ArchiSteamFarm/Steam/Bot.cs
@@ -187,7 +187,7 @@ public sealed class Bot : IAsyncDisposable, IDisposable {
 
 	private IEnumerable<(string FilePath, EFileType FileType)> RelatedFiles {
 		get {
-			foreach (EFileType fileType in Enum.GetValues(typeof(EFileType))) {
+			foreach (EFileType fileType in Enum.GetValues<EFileType>()) {
 				string filePath = GetFilePath(fileType);
 
 				if (string.IsNullOrEmpty(filePath)) {
diff --git a/ArchiSteamFarm/Steam/Cards/CardsFarmer.cs b/ArchiSteamFarm/Steam/Cards/CardsFarmer.cs
index 6459e4c11..3ef7590f5 100644
--- a/ArchiSteamFarm/Steam/Cards/CardsFarmer.cs
+++ b/ArchiSteamFarm/Steam/Cards/CardsFarmer.cs
@@ -920,7 +920,7 @@ public sealed class CardsFarmer : IAsyncDisposable, IDisposable {
 		return keepFarming;
 	}
 
-	private async Task<bool> FarmHours(IReadOnlyCollection<Game> games) {
+	private async Task<bool> FarmHours(HashSet<Game> games) {
 		if ((games == null) || (games.Count == 0)) {
 			throw new ArgumentNullException(nameof(games));
 		}
@@ -979,7 +979,7 @@ public sealed class CardsFarmer : IAsyncDisposable, IDisposable {
 		return keepFarming;
 	}
 
-	private async Task<bool> FarmMultiple(IReadOnlyCollection<Game> games) {
+	private async Task<bool> FarmMultiple(HashSet<Game> games) {
 		if ((games == null) || (games.Count == 0)) {
 			throw new ArgumentNullException(nameof(games));
 		}
diff --git a/ArchiSteamFarm/Steam/Interaction/Commands.cs b/ArchiSteamFarm/Steam/Interaction/Commands.cs
index fa967629f..d2669a10d 100644
--- a/ArchiSteamFarm/Steam/Interaction/Commands.cs
+++ b/ArchiSteamFarm/Steam/Interaction/Commands.cs
@@ -1976,7 +1976,7 @@ public sealed class Commands {
 		return responses.Count > 0 ? string.Join(Environment.NewLine, responses) : null;
 	}
 
-	private async Task<string?> ResponsePlay(EAccess access, IReadOnlyCollection<uint> gameIDs, string? gameName = null) {
+	private async Task<string?> ResponsePlay(EAccess access, HashSet<uint> gameIDs, string? gameName = null) {
 		if (!Enum.IsDefined(access)) {
 			throw new InvalidEnumArgumentException(nameof(access), (int) access, typeof(EAccess));
 		}
@@ -2965,7 +2965,7 @@ public sealed class Commands {
 		return responses.Count > 0 ? string.Join(Environment.NewLine, responses) : null;
 	}
 
-	private async Task<string?> ResponseTransferByRealAppIDs(EAccess access, IReadOnlyCollection<uint> realAppIDs, Bot targetBot, bool exclude) {
+	private async Task<string?> ResponseTransferByRealAppIDs(EAccess access, HashSet<uint> realAppIDs, Bot targetBot, bool exclude) {
 		if (!Enum.IsDefined(access)) {
 			throw new InvalidEnumArgumentException(nameof(access), (int) access, typeof(EAccess));
 		}
diff --git a/ArchiSteamFarm/Steam/Storage/BotDatabase.cs b/ArchiSteamFarm/Steam/Storage/BotDatabase.cs
index 97201a52d..dc54ded52 100644
--- a/ArchiSteamFarm/Steam/Storage/BotDatabase.cs
+++ b/ArchiSteamFarm/Steam/Storage/BotDatabase.cs
@@ -318,8 +318,6 @@ public sealed class BotDatabase : GenericDatabase {
 	}
 
 	internal static bool IsValidGameToRedeemInBackground(DictionaryEntry game) {
-		ArgumentNullException.ThrowIfNull(game);
-
 		string? key = game.Key as string;
 
 		if (string.IsNullOrEmpty(key) || !Utilities.IsValidCdKey(key)) {