code: def update_long(self, **kwargs):
          
          for key, val in six.iteritems(kwargs):
              self.update_arg(key, long=val)
docs: Update the long optional arguments (those with two leading '-')
  
          This method updates the short argument name for the specified function
          arguments as stored in :attr:`unfinished_arguments`
  
          Parameters
          ----------
          ``**kwargs``
              Keywords must be keys in the :attr:`unfinished_arguments`
              dictionary (i.e. keywords of the root functions), values the long
              argument names
  
          Examples
          --------
          Setting::
  
              >>> parser.update_long(something='s', something_else='se')
  
          is basically the same as::
  
              >>> parser.update_arg('something', long='s')
              >>> parser.update_arg('something_else', long='se')
  
          which in turn is basically comparable to::
  
              >>> parser.add_argument('--s', dest='something', ...)
              >>> parser.add_argument('--se', dest='something_else', ...)
  
          See Also
          --------
          update_short, update_longf