+/**
+ * modest_account_protocol_decode_part_to_stream_async:
+ * @self: a #ModestAccountProtocol
+ * @part: a #TnyMimePart
+ * @stream_uri: a string
+ * @stream: a #TnyStream
+ *
+ * This virtual method delegates on the account protocol to decode @part
+ * into @stream, but asynchronously.
+ *
+ * The @stream_uri parameter tells the uri of the resource @stream is
+ * wrapping (if known).
+ *
+ * Returns: %TRUE if @protocol does the decode operation (then we shouldn't expect
+ * callback to happen from this call, %FALSE if modest should do it.
+ */
+gboolean modest_account_protocol_decode_part_to_stream_async (ModestAccountProtocol *self,
+ TnyMimePart *part,
+ const gchar *stream_uri,
+ TnyStream *stream,
+ TnyMimePartCallback callback,
+ TnyStatusCallback status_callback,
+ gpointer user_data);