code: def darken(color, ratio=0.5):
      """Creates a darker version of a color given by an RGB triplet.
  
      This is done by mixing the original color with black using the given
      ratio. A ratio of 1.0 will yield a completely black color, a ratio
      of 0.0 will yield the original color. The alpha values are left intact.
      """
      ratio = 1.0 - ratio
      red, green, blue, alpha = color
      return (red * ratio, green * ratio, blue * ratio, alpha)
  
imports: from abc import ABCMeta, abstractmethod
  from math import ceil
label_desc: Use image node_id 5 for calling a global function with example usage: darken(color, ratio) and returns: unknown,  unknown,  unknown,  alpha