Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type.
This method returns true if an event listener is triggered during any phase of the event flow when an event of the specified type is dispatched to this EventDispatcher object or any of its descendants.
The difference between HasEventListener() and HasBubblingEventListener() is that HasEventListener() examines only the object to which it belongs, whereas HasBubblingEventListener() examines the entire event flow for the event specified by the type parameter.


- eventType (String)
