human
I wrote the below code

    domain_port = destination.split(':')
    domain = domain_port[0]
    port = (int(domain_port[1]) if domain_port[1:] else None)
    endpoint_kw_args = {}
    if (timeout is not None):
        endpoint_kw_args.update(timeout=timeout)
    if (ssl_context_factory is None):
        transport_endpoint = HostnameEndpoint
        default_port = 8008
    else:
        def transport_endpoint(reactor, host, port, timeout):
            return wrapClientTLS(ssl_context_factory, HostnameEndpoint(reactor, host, port, timeout=timeout))
        default_port = 8448
    if (port is None):
        return _WrappingEndpointFac(SRVClientEndpoint(reactor, 'matrix', domain, protocol='tcp', default_port=default_port, endpoint=transport_endpoint, endpoint_kw_args=endpoint_kw_args))
    else:
        return _WrappingEndpointFac(transport_endpoint(reactor, domain, port, **endpoint_kw_args))

What's a good function header?

Here's a good function header?
assistant
#Here's a good function header.

def matrix_federation_endpoint(reactor, destination, ssl_context_factory=None, timeout=None):