# Objective
Reduce the size of `bevy_utils`
(https://github.com/bevyengine/bevy/issues/11478)
## Solution
Move `EntityHash` related types into `bevy_ecs`. This also allows us
access to `Entity`, which means we no longer need `EntityHashMap`'s
first generic argument.
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## Changelog
- Moved `bevy::utils::{EntityHash, EntityHasher, EntityHashMap,
EntityHashSet}` into `bevy::ecs::entity::hash` .
- Removed `EntityHashMap`'s first generic argument. It is now hardcoded
to always be `Entity`.
## Migration Guide
- Uses of `bevy::utils::{EntityHash, EntityHasher, EntityHashMap,
EntityHashSet}` now have to be imported from `bevy::ecs::entity::hash`.
- Uses of `EntityHashMap` no longer have to specify the first generic
parameter. It is now hardcoded to always be `Entity`.