#NEWLINE# def test_null_node_boundary( self ) : #NEWLINE# #INDENT# 'null graph has empty node boundaries' #NEWLINE# null = self . null #NEWLINE# assert_equal ( nx . node_boundary ( null , [ ] ) , [ ] ) #NEWLINE# assert_equal ( nx . node_boundary ( null , [ ] , [ ] ) , [ ] ) #NEWLINE# assert_equal ( nx . node_boundary ( null , [ 1 , 2 , 3 ] ) , [ ] ) #NEWLINE# assert_equal ( nx . node_boundary ( null , [ 1 , 2 , 3 ] , [ 4 , 5 , 6 ] ) , [ ] ) #NEWLINE# assert_equal ( nx . node_boundary ( null , [ 1 , 2 , 3 ] , [ 3 , 4 , 5 ] ) , [ ] )