class_docstr: Mimic xarray Dataset object.
class_docstr_tok: ["Mimic","xarray","Dataset","object","."]
docstr: Mimic getitem method.
docstr_tok: ["Mimic","getitem","method","."]
code: def __getitem__(self, key):
      """Mimic getitem method."""
      return self.info[key]
  
imports: import unittest
  from unittest import mock
  import dask.array
  import numpy
  import xarray
  from pytest import approx, raises
label_desc: Use image node_id 2 for calling the FakeDataset obj's underlying member method code with example usage: obj.__getitem__(key) and returns: self