#NEWLINE# def test_merge( self ) : #NEWLINE# #INDENT# g = graph . DiGraph ( ) #NEWLINE# g . add_node ( 'a' ) #NEWLINE# g . add_node ( 'b' ) #NEWLINE# g2 = graph . DiGraph ( ) #NEWLINE# g2 . add_node ( 'c' ) #NEWLINE# g3 = graph . merge_graphs ( g3 , g2 ) #NEWLINE# self . assertEqual ( 3 , len ( g3 ) )