code: def _generate_ascii(self, matrix, foreground, background):
          
  
          return "\n".join(["".join([foreground if cell else background for cell in row]) for row in matrix])
docs: Generates an identicon "image" in the ASCII format. The image will just
          output the matrix used to generate the identicon.
  
          Arguments:
  
            matrix - Matrix describing which blocks in the identicon should be
            painted with foreground (background if inverted) colour.
  
            foreground - Character which should be used for representing
            foreground.
  
            background - Character which should be used for representing
            background.
  
          Returns:
  
            ASCII representation of an identicon image, where one block is one
            character.