code: def grayscale_image_rgb(*args, **kwargs):
      """Takes same arguments as image"""
      output = image(*args, channels=1, **kwargs)
      return tf.tile(output, (1, 1, 1, 3))
  
imports: import tensorflow
  from lucid.optvis.param.color import to_valid_rgb
  from lucid.optvis.param.spatial import pixel_image, fft_image
label_desc: Use image node_id 2 for calling a global function with example usage: grayscale_image_rgb() and returns: tf