func (db *DBusFake) SystemBus() (Connection, error) {
	if db.systemBus != nil {
		return db.systemBus, nil
	} else {
		return nil, fmt.Errorf("DBus is not running")
	}
}
SystemBus is part of Interface
package dbus
import (
	"fmt"
	"sync"
	godbus "github.com/godbus/dbus"
)
type DBusFake struct {
	systemBus  *DBusFakeConnection
	sessionBus *DBusFakeConnection
}
type DBusFakeConnection struct {
	lock           sync.Mutex
	busObject      *fakeObject
	objects        map[string]*fakeObject
	signalHandlers []chan<- *godbus.Signal
}
type DBusFakeHandler func(method string, args ...interface{}) ([]interface{}, error)
type fakeObject struct {
	handler DBusFakeHandler
}
type fakeCall struct {
	ret []interface{}
	err error
}
func NewFake(systemBus *DBusFakeConnection, sessionBus *DBusFakeConnection) *DBusFake {
	return &DBusFake{systemBus, sessionBus}
}
func NewFakeConnection() *DBusFakeConnection {
	return &DBusFakeConnection{
		objects: make(map[string]*fakeObject),
	}
}