def value_count(self, key):
check_not_none(key, "<STR_LIT>")<EOL>key_data = self._to_data(key)<EOL>return self._encode_invoke_on_key(multi_map_value_count_codec, key_data, key=key_data,<EOL>thread_id=thread_id())<EOL>
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.