#NEWLINE# def add_edge( self , x , y , label = None ) : #NEWLINE# #INDENT# 'Add an edge from distribution *x* to distribution *y* with the given\n        *label*.\n\n        :type x: :class:`distutils2.database.InstalledDistribution` or\n                 :class:`distutils2.database.EggInfoDistribution`\n        :type y: :class:`distutils2.database.InstalledDistribution` or\n                 :class:`distutils2.database.EggInfoDistribution`\n        :type label: ``str`` or ``None``\n        ' #NEWLINE# self . adjacency_list [ x ] . append ( ( y , label ) ) #NEWLINE# if ( x not in self . reverse_list [ label ] ) : #NEWLINE# #INDENT# self . reverse_list [ y ] . append ( x )