Unity - Scripting API:

public static function Execute(target: GameObject, eventData: EventSystems.BaseEventData, functor: EventFunction<T>): bool;

public static bool Execute(GameObject target, EventSystems.BaseEventData eventData, EventFunction<T> functor);

Parameters

target	Target GameObject.
eventData	Data associated with the Executing event.
functor	Function to execute on the gameObject components.

bool Was there a handler for the event.

Execute the event of type T : IEventSystemHandler on GameObject.

The event will be executed on all components on the GameObject that can handle it.