def _get_filter_modifier(self, field):
        """Detect the filter modifier"""
        tokens = field.split(FIELD_SEPARATOR)
        if len(tokens) == 1:
            return field, ""
        if tokens[-1] in self.FILTER_OPERATORS.keys():
            return u'.'.join(tokens[:-1]), tokens[-1]
        return u'.'.join(tokens), ""
Detect the filter modifier