code: def __next__(self):
      ratios = [
          count / len(itr) for count, itr in zip(self._counts, self.itr)
      ]
      idx = ratios.index(min(ratios))
      self._counts[idx] += 1
      return next(self.itr[idx])
  
imports: from collections import OrderedDict
  import numpy
  from fairseq.data import BaseWrapperDataset, FairseqDataset, iterators
label_desc: Use image node_id 4 for calling the MultiItr obj's underlying member method code with example usage: obj.__next__() and returns: next