class_docstr: Mixing strategy that should be used in Data Iterator.
docstr: Initilize neccessary attr.
code: def __init__(self, iterables, weights):
      """Initilize neccessary attr."""
      self._valid_iterable(iterables, weights)
      self.iterables = iterables
      self.weights = weights
  
imports: import torch
  from itertools import cycle
  from onmt.constants import CorpusTask, ModelTask
  from onmt.inputters.text_corpus import get_corpora, build_corpora_iters
  from onmt.inputters.text_utils import text_sort_key, process, numericalize, tensorify, _addcopykeys
  from onmt.transforms import make_transforms
  from onmt.utils.logging import init_logger, logger
  from onmt.utils.misc import RandomShuffler
  from torch.utils.data import DataLoader
label_desc: Use image node_id 1 to create a new MixingStrategy object from inherited base classes: object with example: obj = MixingStrategy(iterables, weights)