returns the pattern specified in a response schema

def _get_pattern_for_schema(self, schema_name, httpStatus):
        '''
        returns the pattern specified in a response schema
        '''
        defaultPattern = '.+' if self._is_http_error_rescode(httpStatus) else '.*'
        model = self._models().get(schema_name)
        patterns = self._find_patterns(model)
        return patterns[0] if patterns else defaultPattern