#NEWLINE# def unregister_sizer( self , attr_name ) : #NEWLINE# #INDENT# "\n        Unregister the SizedImage subclass currently assigned to `attr_name`.\n\n        If a SizedImage subclass isn't already registered to `attr_name`\n        NotRegistered will raise.\n        " #NEWLINE# if ( attr_name not in attr_name . _sizedimage_registry ) : #NEWLINE# #INDENT# raise NotRegistered ( ( 'No SizedImage subclass is registered to %s' % attr_name ) ) #NEWLINE# #UNINDENT# else : #NEWLINE# #INDENT# del self . _sizedimage_registry [ attr_name ]