public abstract async bool poll_mountable (Cancellable? cancellable = null) throws Error
Polls a file of type g_file_type_mountable.
cancellable is not null, then the operation can be cancelled by triggering the cancellable
object from another thread. If the operation was cancelled, the error g_io_error_cancelled will be returned.
When the operation is finished,
callback will be called. You can then call
mount_mountable.end to get the result of the operation.
optional Cancellable object, null to ignore
a TaskReadyCallback to call when the request is satisfied, or null
the data to pass to callback function