code: def received(self, limit=None):
          
          return list(itertools.islice((itertools.filterfalse(lambda x: x[1].sent, self.store)), limit))[::-1]
docs: Returns all the events that have been received (excluding sent events), until a limit if defined
  
          Args:
            limit (int, optional): the max length of the events to return (Default value = None)
  
          Returns:
            list: a list of received events