#NEWLINE# def add_child( self , child_node ) : #NEWLINE# #INDENT# '\n            Adds an existing node as a new child\n            for the current node.\n            \n            ' #NEWLINE# ( str_ind , substr_start , _ ) = child_node . arc ( ) #NEWLINE# child_node . strings_collection = self . strings_collection #NEWLINE# self . children [ self . strings_collection [ str_ind ] [ substr_start ] ] = child_node #NEWLINE# child_node . parent = self