class_docstr: Simple Dataset wrapper for lists and arrays.
  
  Parameters
  ----------
  data : dataset-like object
      Any object that implements `len()` and `[]`.
code: def __getitem__(self, idx):
      return self._data[idx]
  
imports: import os
  from ...None import recordio, ndarray
  from ...util import default_array
label_desc: Use image node_id 3 for calling the SimpleDataset obj's underlying member method code with example usage: obj.__getitem__(idx) and returns: self