code: def test_octree_quantize():
      image = hopper()
      converted = image.quantize(100, Image.FASTOCTREE)
      assert converted.mode == "P"
      assert_image_similar(converted.convert("RGB"), image, 20)
      assert len(converted.getcolors()) == 100
  
file_path: pillow-simd/Tests/test_image_quantize.py
imports: import pytest
  from PIL import Image
  from .helper import assert_image_similar, hopper, is_ppc64le
label_desc: Use image node_id 3 for calling a global function with example usage: test_octree_quantize() without return types