code: def _overlay_heatmap(heatmap, image):
      # type: (Image, Image) -> Image
      """
      Blend (combine) ``heatmap`` over ``image``,
      using alpha channel values appropriately (must have mode `RGBA`).
      Output is 'RGBA'.
      """
      # note that the order of alpha_composite arguments matters
      overlayed_image = Image.alpha_composite(image, heatmap)
      return overlayed_image
  
file_path: eli5/eli5/formatters/image.py
imports: from __future__ import absolute_import
  from typing import Union, Optional, Callable
  import numpy
  from PIL import Image
  import matplotlib.cm
  from eli5.base import Explanation
label_desc: Use image node_id 8 for calling a global function with example usage: _overlay_heatmap(heatmap, image) and returns: overlayed_image