code: def build_dataset(prefix, data, coder):
      with HuffmanMMapIndexedDatasetBuilder(prefix, coder) as builder:
          for sentence in data:
              builder.add_item(sentence)
  
imports: import os
  import typing
  import unittest
  from collections import Counter
  from tempfile import NamedTemporaryFile, TemporaryDirectory
  from fairseq.data import Dictionary, indexed_dataset
  from fairseq.data.huffman import HuffmanCodeBuilder, HuffmanCoder, HuffmanMMapIndexedDataset, HuffmanMMapIndexedDatasetBuilder
  from tests.utils import POPULATION, make_data, sizes
label_desc: Use image node_id 3 for calling a global function with example usage: build_dataset(prefix, data, coder) without return types