Helper function used in service implementations to finish handling invocations of the LoopSetup D-Bus method.
If you instead want to finish handling an invocation by returning an error, use return_error or similar.
This method will free invocation, you cannot use it afterwards.
| this |
A Manager. |
| invocation |
A DBusMethodInvocation. |
| fd_list |
A UnixFDList or |
| resulting_device |
Parameter to return. |