Manipulates the audio it receives for a given effect.
An audio effect instance manipulates the audio it receives for a given effect. This instance is automatically created by an [AudioEffect] when it is added to a bus, and should usually not be created directly. If necessary, it can be fetched at run-time with [method AudioServer.get_bus_effect_instance].
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Called by the [AudioServer] to process this effect. When [method _process_silence] is not overridden or it returns [code]false[/code], this method is called only when the bus is active. [b]Note:[/b] It is not useful to override this method in GDScript or C#. Only GDExtension can take advantage of it.
Override this method to customize the processing behavior of this effect instance. Should return [code]true[/code] to force the [AudioServer] to always call [method _process], even if the bus has been muted or cannot otherwise be heard.