def start_event(self, event_type, *args, dt=<NUM_LIT:1>/<NUM_LIT>):
<EOL>if not any(self.__yield_handlers(event_type)):<EOL><INDENT>return<EOL><DEDENT>def on_time_interval(dt): <EOL><INDENT>self.dispatch_event(event_type, *args, dt)<EOL><DEDENT>pyglet.clock.schedule_interval(on_time_interval, dt)<EOL>self.__timers[event_type] = on_time_interval<EOL>
Begin dispatching the given event at the given frequency.

Calling this method will cause an event of type *event_type* with 
arguments *args* to be dispatched every *dt* seconds.  This will 
continue until `stop_event()` is called for the same event.

These continuously firing events are useful if, for example, you want 
to make a button that scrolls for as long as it's being held.