extern mlt_field mlt_tractor_field( mlt_tractor self );
extern mlt_multitrack mlt_tractor_multitrack( mlt_tractor self );
extern int mlt_tractor_connect( mlt_tractor self, mlt_service service );
+extern void mlt_tractor_refresh( mlt_tractor self );
+extern int mlt_tractor_set_track( mlt_tractor self, mlt_producer producer, int index );
+extern mlt_producer mlt_tractor_get_track( mlt_tractor self, int index );
extern void mlt_tractor_close( mlt_tractor self );
#endif