def register_event(self, direction, verb, child_fn, priority=<NUM_LIT:10>):
if verb not in self._event_handlers:<EOL><INDENT>self._event_handlers[verb] = []<EOL><DEDENT>self._event_handlers[verb].append({<EOL>'<STR_LIT>': child_fn,<EOL>'<STR_LIT>': direction,<EOL>'<STR_LIT>': priority,<EOL>})<EOL>for name, server in self.servers.items():<EOL><INDENT>server.register_event(direction, verb, child_fn, priority=priority)<EOL><DEDENT>
Register an event with all servers.

        Args:
            direction (str): `in`, `out`, `both`, `raw`.
            verb (str): Event name.
            child_fn (function): Handler function.
            priority (int): Handler priority (lower priority executes first).