NOTE
Decorator Pattern
Adding composable behavior around an object without changing the wrapped implementation.
This is a historical learning note and may contain outdated or incomplete understanding.
A decorator wraps an object with the same behavioral contract and adds functionality before or after delegation. Multiple decorators can be composed for concerns such as buffering, compression, metrics, tracing, or authorization.
Ordering matters when decorators have side effects. Keep wrappers transparent where possible and avoid deep chains whose behavior becomes difficult to reason about.