code: def build_corpora_iters(
      corpora,
      transforms,
      corpora_info,
      skip_empty_level="warning",
      stride=1,
      offset=0,
  ):
      """Return `ParallelCorpusIterator` for all corpora defined in opts."""
      corpora_iters = dict()
      for c_id, corpus in corpora.items():
          transform_names = corpora_info[c_id].get("transforms", [])
          corpus_transform = [
              transforms[name]
              for name in transform_names
              if name in transforms
          ]
          transform_pipe = TransformPipe.build_from(corpus_transform)
          corpus_iter = ParallelCorpusIterator(
              corpus,
              transform_pipe,
              skip_empty_level=skip_empty_level,
              stride=stride,
              offset=offset,
          )
          corpora_iters[c_id] = corpus_iter
      return corpora_iters
  
imports: import os
  from onmt.utils.logging import logger
  from onmt.constants import CorpusName, CorpusTask
  from onmt.transforms import TransformPipe
  from onmt.inputters.text_utils import process, parse_features, append_features_to_text
  from contextlib import contextmanager
  import itertools
label_desc: Use image node_id 3 for calling a global function with example usage: build_corpora_iters(corpora, transforms, corpora_info, skip_empty_level, stride, offset) and returns: corpora_iters