@fluent<EOL><INDENT>def function(self, function_name, word):<DEDENT>
word = self._parse_filter_word(word)<EOL>self._add_filter(<EOL>*self._prepare_function(function_name, self._attribute, word,<EOL>self._negation))<EOL>return self<EOL>
Apply a function on given word

        :param str function_name: function to apply
        :param str word: word to apply function on
        :rtype: Query