{"error":{"root_cause":[{"type":"parsing_exception","reason":"[match] unknown token [VALUE_NULL] after [query]","line":1,"col":64}],"type":"x_content_parse_exception","reason":"[1:64] [bool] failed to parse field [must]","caused_by":{"type":"parsing_exception","reason":"[match] unknown token [VALUE_NULL] after [query]","line":1,"col":64}},"status":400}