gDriveEjectWithOperationFinish with the drive
and GAsyncResult data returned in the callback.gDriveEjectWithOperation(object, flags, mount.operation, cancellable = NULL, callback, user.data = NULL)objectGDrive.flagsmount.operationGMountOperation or NULL to avoid user interaction.cancellableGCancellable object, NULL to ignore.callbackGAsyncReadyCallback, or NULL.user.datacallback.