code: def histogram_indexer(self):
      node_size = 2
      feature_bin_sizes = [3, 2]
      return HistogramIndexer(node_size, feature_bin_sizes)
  
file_path: FATE/python/fate/test/histogram/indexer.py
imports: import pytest
  from fate_utils.histogram import HistogramIndexer, Shuffler
label_desc: Use image node_id 1 for calling the TestHistogramIndexer obj's underlying member method code with example usage: obj.histogram_indexer() and returns: HistogramIndexer