#NEWLINE# def __set__( self , instance , value ) : #NEWLINE# #INDENT# previous_file = instance . __dict__ . get ( self . field . name ) #NEWLINE# super ( ImageFileDescriptor , self ) . __set__ ( instance , value ) #NEWLINE# if ( previous_file is not None ) : #NEWLINE# #INDENT# self . field . update_dimension_fields ( instance , force = True )