code: def test_get_item(self):
      file_path = os.path.join(self.resource_path, "orca/data/json")
      data_shard = zoo.orca.data.pandas.read_json(
          file_path, orient="columns", lines=True
      )
      selected_shard = data_shard["value"]
      assert data_shard.is_cached(), "data_shard should be cached"
      assert (
          not selected_shard.is_cached()
      ), "selected_shard should not be cached"
      data1 = data_shard.collect()
      data2 = selected_shard.collect()
      assert (
          data1[0]["value"].values[0] == data2[0][0]
      ), "value should be same"
      assert (
          data1[1]["value"].values[0] == data2[1][0]
      ), "value should be same"
      with self.assertRaises(Exception) as context:
          len(data_shard["abc"])
      self.assertTrue(
          "Invalid key for this XShards" in str(context.exception)
      )
  
imports: import os.path
  import shutil
  import pytest
  from unittest import TestCase
  import zoo.orca.data
  import zoo.orca.data.pandas
  from zoo.orca import OrcaContext
  from zoo.orca.data import SharedValue
  from zoo.common.nncontext import *
  from zoo.orca.data import SparkXShards
label_desc: Use image node_id 16 for calling the TestSparkXShards obj's underlying member method code with example usage: obj.test_get_item() without return types