libmachine/drivers/rpc/server_driver.go
func (r *RPCServerDriver) GetSSHPort(_ *struct{}, reply *int) error {
	port, err := r.ActualDriver.GetSSHPort()
	*reply = port
	return err
}
func (r *RPCServerDriver) GetSSHPort(_ *struct{}, reply *int) error {
	port, err := r.ActualDriver.GetSSHPort()
	*reply = port
	return err
}
// GetSSHPort returns port for use with ssh