<s> from traits . api import HasTraits , Bool <EOL> class TransformPlugin ( HasTraits ) : <EOL> active = Bool ( False ) <EOL> def process_frame ( self , frame ) : <EOL> if not self . active : <EOL> return frame <EOL> return self . _process ( frame ) <EOL> def _active_changed ( self , value ) : <EOL> if value : <EOL> self . activate ( ) <EOL> else : <EOL> self . deactivate ( ) <EOL> def activate ( self ) : <EOL> pass <EOL> def deactivate ( self ) : <EOL> pass </s>
