code: def _display_buffer(self, buffer ):
          
          self._command([
              self.CMD_SSD1306_SET_COLUMN_ADDR,
              0, self.width-1,
              self.CMD_SSD1306_SET_PAGE_ADDR,
              0, self._mem_pages - 1
              ])
          self._data( buffer )
docs: !
          \~english
          Send buffer data to physical display.
          @param buffer: sent to display chip of data.
  
          \~chinese
          将缓冲区数据发送到物理显示。
          @param buffer: 送到显示芯片的数据。