Transactional implementation of :func:`MultiMap.value_count(key)
        <hazelcast.proxy.multi_map.MultiMap.value_count>`

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

def value_count(self, key):
        """
        Transactional implementation of :func:`MultiMap.value_count(key)
        <hazelcast.proxy.multi_map.MultiMap.value_count>`

        :param key: (object), the key whose number of values is to be returned.
        :return: (int), the number of values matching the given key in the multimap.
        """
        check_not_none(key, "key can't be none")
        return self._encode_invoke(transactional_multi_map_value_count_codec, key=self._to_data(key))