code: def create_channel(self, width, height):
          
          if self.channel_mode is None:
              return self.create(width, height)
          return Image.new(self.channel_mode, (width, height))
docs: Create a channel.
  
          Parameters
          ----------
          width: `int`
              Image width.
          height: `int`
              Image height.
  
          Returns
          -------
          `PIL.Image.Image`