docs: def _xbm(code, scale=1, quiet_zone=4):
      """This function will format the QR code as a X BitMap.
      This can be used to display the QR code with Tkinter.
      """
      try:
          str = unicode  # Python 2
      except NameError:
          str = __builtins__['str']
          
      buf = io.StringIO()
      
      # Calculate the width in pixels
      pixel_width = (len(code[0]) + quiet_zone * 2) * scale
      
      # Add the size information and open the pixel data section
      buf.write('#define im_width ')
      buf.write(str(pixel_width))
      buf.write('\n')
      buf.write('#define im_height ')
      buf.write(str(pixel_width))
      buf.write('\n')
      buf.write('static char im_bits[] = {\n')
      
      # Calculate the number of bytes per row
      byte_width = int(math.ceil(pixel_width / 8.0))
      
      # Add the top quiet zone
      buf.write(('0x00,' * byte_width + '\n') * quiet_zone * scale)
      for row in code:
          # Add the left quiet zone
          row_bits = '0' * quiet_zone * scale
          # Add the actual QR code
          for pixel in row:
              row_bits += str(pixel) * scale
          # Add the right quiet zone
          row_bits += '0' * quiet_zone * scale
          # Format the row
          formated_row = ''
          for b in range(byte_width):
              formated_row += '0x{0:02x},'.format(int(row_bits[:8][::-1], 2))
              row_bits = row_bits[8:]
          formated_row += '\n'
          # Add the formatted row
          buf.write(formated_row * scale)
      # Add the bottom quiet zone and close the pixel data section
      buf.write(('0x00,' * byte_width + '\n') * quiet_zone * scale)
      buf.write('};')
      
      return buf.getvalue()