code: func (t *NetTransport) GetAutoBindPort() int {
  	// We made sure there's at least one TCP listener, and that one's
  	// port was applied to all the others for the dynamic bind case.
  	return t.tcpListeners[0].Addr().(*net.TCPAddr).Port
  }
docs: // GetAutoBindPort returns the bind port that was automatically given by the
  // kernel, if a bind port of 0 was given.