code: def _make_verb_helper(verb_func, add_groups=False):
      
  
      @wraps(verb_func)
      def _verb_func(verb):
          verb.expressions, new_columns = build_expressions(verb)
          if add_groups:
              verb.groups = new_columns
          return verb_func(verb)
  
      return _verb_func
docs: Create function that prepares verb for the verb function
  
      The functions created add expressions to be evaluated to
      the verb, then call the core verb function
  
      Parameters
      ----------
      verb_func : function
          Core verb function. This is the function called after
          expressions created and added to the verb. The core
          function should be one of those that implement verbs that
          evaluate expressions.
      add_groups : bool
          If True, a groups attribute is added to the verb. The
          groups are the columns created after evaluating the
          expressions.
  
      Returns
      -------
      out : function
          A function that implements a helper verb.