def METHOD_NAME(self, event_data):
    """
    Sets event_data as new item of occurrence ret.
    :param event_data: data to set as value of occurrence.
    :return: None
    """
    """Should be used to set final result"""
    if self.done():
        raise ResultAlreadySet(self)
    if self._occurred is None:
        self._occurred = []
    self._occurred.append(event_data)
    if self.till_occurs_times > 0:
        if len(self._occurred) >= self.till_occurs_times:
            self.set_result(self._occurred)
    self.notify()