docs: def register_response(self, correlation_id=None):
  		"""
  		Register the receiving of a RPC response. Will return the given correlation_id after registering, or if correlation_id is None, will
  		generate a correlation_id and return it after registering. If the given correlation_id has already been used, an KeyError will be
  		raised.
  
  		UUID version 1 will be used when generating correlation_ids. Depending on the underlying system and implementation, this will guarantee
  		that generated values are unique between workers. At least CPython guarantees this behaviour.
  
  		Parameters
  		----------
  		correlation_id: string
  			Identifier under which to expect a RPC callback. If None, a correlation_id will be generated.
  
  		"""
  		if not correlation_id:
  			correlation_id = str(uuid.uuid1())
  
  		if correlation_id in self.responses:
  			raise KeyError("Correlation_id {0} was already registered, and therefor not unique.".format(correlation_id))
  
  		self.responses[correlation_id] = None
  		return correlation_id