# Objective
The `BuildChildren` and `BuildWorldChildren` traits are mostly
identical, so I decided to try and merge them. I'm not sure of the
history, maybe they were added before GATs existed.
## Solution
- Add an associated type to `BuildChildren` which reflects the prior
differences between the `BuildChildren` and `BuildWorldChildren` traits.
- Add `ChildBuild` trait that is the bounds for
`BuildChildren::Builder`, with impls for `ChildBuilder` and
`WorldChildBuilder`.
- Remove `BuildWorldChildren` trait and replace it with an impl of
`BuildChildren` for `EntityWorldMut`.
## Testing
I ran several of the examples that use entity hierarchies, mainly UI.
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## Changelog
n/a
## Migration Guide
n/a
# Objective
- Currently the fps_overlay affects any other ui node spawned. This
should not happen
## Solution
- Use position absolute and a ZIndex of `i32::MAX - 32`
- I also modified the example a little bit to center it correctly. It
only worked previously because the overlay was pushing it down. I also
took the opportunity to simplify the text spawning code a little bit.
# Objective
- Part of #12351
- Add fps overlay
## Solution
- Create `FpsOverlayPlugin`
- Allow for configuration through resource `FpsOverlayConfig`
- Allow for configuration during runtime
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Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
