code: def set_write_buffer_limits(self, high=None, low=None):
          
          if high is None:
              high = self.write_buffer_size
          if low is None:
              low = high // 2
          if low > high:
              low = high
          self._write_buffer_high = high
          self._write_buffer_low = low
docs: Set the low and high watermark for the write buffer.