#NEWLINE# def test_directed( self ) : #NEWLINE# #INDENT# 'Tests the edge boundary of a directed graph.' #NEWLINE# G = nx . DiGraph ( [ ( 0 , 1 ) , ( 1 , 2 ) , ( 2 , 3 ) , ( 3 , 4 ) , ( 4 , 0 ) ] ) #NEWLINE# S = { 0 , 1 } #NEWLINE# boundary = list ( nx . edge_boundary ( G , S ) ) #NEWLINE# expected = [ ( 1 , 2 ) ] #NEWLINE# assert_equal ( boundary , expected )