code: def _rgb2id(color):
      return color[0] + 256 * color[1] + 256 * 256 * color[2]
  
file_path: chainercv/chainercv/datasets/coco/coco_semantic_segmentation_dataset.py
imports: import json
  import numpy
  import os
  from chainercv.chainer_experimental.datasets.sliceable import GetterDataset
  from chainercv.datasets.coco.coco_utils import get_coco
  from chainercv import utils
label_desc: Use image node_id 1 for calling a global function with example usage: _rgb2id(color) and returns: unknown