def _flatten_response_never_received(e):
    if hasattr(e, "reasons"):
        return ", ".join(
            _flatten_response_never_received(f.value)
            for f in e.reasons
        )
    else:
        return "%s: %s" % (type(e).__name__, e.message,)
dataset/ETHPy150Open matrix-org/synapse/synapse/http/matrixfederationclient.py/_flatten_response_never_received/original