Function parse_plain_function_response 

pub fn parse_plain_function_response(
    payload: &[u8],
    capabilities: ClientCapabilities,
) -> Result<bool>

Scan a plain function response (ping/commit/rollback) for a server error. Unknown message types end the scan without error so payload shapes that were previously tolerated (responses used to go unparsed) keep working. Returns whether a server-side transaction is in progress, sampled from the final end-of-call status bit (reference protocol.pyx _process_call_status).