'Removes a currently processing entry from the queue.
:returns: True if element was removed successfully, False otherwise.
:rtype: bool'

def consume(self):

    if ((not (self.processing_element is None)) and self.holds_lock):
        (id_, value) = self.processing_element
        with self.client.transaction() as transaction:
            transaction.delete('{path}/{id}'.format(path=self._entries_path, id=id_))
            transaction.delete('{path}/{id}'.format(path=self._lock_path, id=id_))
        self.processing_element = None
        return True
    else:
        return False
