a gio.input_stream.InputStream to read the serialized content from
the mime type to deserialize from
the GType to deserialize from
the I/O priority of the operation
optional gio.cancellable.Cancellable object
callback to call when the operation is done
Read content from the given input stream and deserialize it, asynchronously.
The default I/O priority is G_PRIORITY_DEFAULT (i.e. 0), and lower numbers indicate a higher priority.
When the operation is finished, callback will be called. You must then call funcGdk.content_deserialize_finish to get the result of the operation.