class_docstr: Wrapper over ndarray that can contain tensors on multiple devices.
  
  This is returned by extensions.pmap, and contains the individual tensors on
  different devices.
code: def __getitem__(self, i):
      return self.tensors[i]
  
imports: import numpy
  import six
  import tensorflow.compat.v2
  from trax.tf_numpy.numpy_impl import dtypes
label_desc: Use image node_id 2 for calling the ShardedNdArray obj's underlying member method code with example usage: obj.__getitem__(i) and returns: self