class_docstr: A dataset that combines multiple dataset-like objects, e.g.
  Datasets, lists, arrays, etc.
  
  The i-th sample is defined as `(x1[i], x2[i], ...)`.
  
  Parameters
  ----------
  *args : one or more dataset-like objects
      The data arrays.
code: def __getitem__(self, idx):
      if len(self._data) == 1:
          return self._data[0][idx]
      else:
          return tuple(data[idx] for data in self._data)
  
imports: import os
  from ...None import recordio, ndarray
  from ...util import default_array
label_desc: Use image node_id 2 for calling the ArrayDataset obj's underlying member method code with example usage: obj.__getitem__(idx) and returns: self, tuple