code: def add(self, string: (str, list)):
          
          if len(self._entries) == 1:
              self._entries[0].delete(0, 'end')
              self._entries[0].insert(0, string)
          else:
              if len(string) != len(self._entries):
                  raise ValueError('the "string" list must be '
                                   'equal to the number of entries')
  
              for i, e in enumerate(self._entries):
                  self._entries[i].delete(0, 'end')
                  self._entries[i].insert(0, string[i])
docs: Clear the contents of the entry field and
          insert the contents of string.
  
          :param string: an str containing the text to display
          :return: