code: def _set_batch(self, batch, fg, bg, bgblend=1, nullChar=False):
          
          for (x, y), char in batch:
              self._set_char(x, y, char, fg, bg, bgblend)
docs: Try to perform a batch operation otherwise fall back to _set_char.
          If fg and bg are defined then this is faster but not by very
          much.
  
          if any character is None then nullChar is True
  
          batch is a iterable of [(x, y), ch] items