Returns the number of values that match the given key in the multimap.

        **Warning: This method uses __hash__ and __eq__ methods of binary form of the key, not the actual implementations
        of __hash__ and __eq__ defined in key's class.**

        :param key: (object), the key whose values count is to be returned.
        :return: (int), the number of values that match the given key in the multimap.

def value_count(self, key):
        """
        Returns the number of values that match the given key in the multimap.

        **Warning: This method uses __hash__ and __eq__ methods of binary form of the key, not the actual implementations
        of __hash__ and __eq__ defined in key's class.**

        :param key: (object), the key whose values count is to be returned.
        :return: (int), the number of values that match the given key in the multimap.
        """
        check_not_none(key, "key can't be None")
        key_data = self._to_data(key)
        return self._encode_invoke_on_key(multi_map_value_count_codec, key_data, key=key_data,
                                          thread_id=thread_id())