code: def get_split_num_data_shards(self, split):
      if split in self._num_shards_dict:
          return self._num_shards_dict[split]
      num_shards_dict = {}
      data_paths, lang_pairs = self.get_data_paths_and_lang_pairs(split)
  
      for data_category, paths in data_paths.items():
          if data_category not in lang_pairs:
              continue
          paths = utils.split_paths(paths)
          shards_dict = self._get_shard_num_dict(split, paths)
          lang_dirs = [
              lang_pair.split("-")
              for lang_pair in lang_pairs[data_category]
          ]
          lang_dirs = [
              x if len(x) > 1 else (x[0], x[0]) for x in lang_dirs
          ]
          for src, tgt in lang_dirs:
              key = self.get_dataset_key(data_category, src, tgt)
              if "mono_" in data_category:
                  # monolingual data requires tgt only
                  assert src is None or src == tgt, (
                      f"error: src={src}, "
                      f"tgt={tgt} for data_category={data_category}"
                  )
                  num_shards_dict[key] = shards_dict[tgt]
              else:
                  if f"{src}-{tgt}" in shards_dict:
                      num_shards_dict[key] = shards_dict[f"{src}-{tgt}"]
                  elif f"{tgt}-{src}" in shards_dict:
                      # follow the fairseq tradition to use reversed direction data if it is not available
                      num_shards_dict[key] = shards_dict[f"{tgt}-{src}"]
      self._num_shards_dict[split] = num_shards_dict
      logger.info(f"[{split}] num of shards: {num_shards_dict}")
      return num_shards_dict
  
imports: import itertools
  import json
  import logging
  import math
  import os
  from collections import OrderedDict, defaultdict
  from argparse import ArgumentError
  from fairseq import utils
  from fairseq.data import AppendTokenDataset, ConcatDataset, Dictionary, LanguagePairDataset, PrependTokenDataset, SampledMultiDataset, SampledMultiEpochDataset, StripTokenDataset, TransformEosLangPairDataset, TruncateDataset, data_utils, indexed_dataset
  from fairseq.data.multilingual.multilingual_utils import EncoderLangtok, LangTokSpec, LangTokStyle, augment_dictionary, get_lang_tok
  from fairseq.data.multilingual.sampled_multi_dataset import CollateFormat
  from fairseq.file_io import PathManager
  from fairseq.utils import FileContentsAction, csv_str_list, eval_str_dict
label_desc: Use image node_id 28 for calling the MultilingualDatasetManager obj's underlying member method code with example usage: obj.get_split_num_data_shards(split) and returns: num_shards_dict, self