code: def debug_print_tree( self, spacing='' ):
          ''' *Debug only* method for outputting the tree. '''
          print (spacing+" "+str(self.word_id)+" "+str(self.text))
          if (self.children):
              spacing=spacing+"  "
              for child in self.children:
                  child.debug_print_tree(spacingf debug_print_tree( self, spacing='' ):
          ''' *Debug only* method for outputting the tree. '''
          print (spacing+" "+str(self.word_id)+" "+str(self.text))
          if (self.children):
              spacing=spacing+"  "
              for child in self.children:
                  child.debug_print_tree(spacing)
docs: *Debug only* method for outputting the tree.