code: def test_update_predict_xshard(self):
      def get_xshards(key):
          rdd = self.sc.range(0, 110).map(lambda x: np.array([x] * 50))
          shards = rdd.mapPartitions(lambda iter: chunks(iter, 5)).map(
              lambda x: {key: np.stack(x)}
          )
          shards = SparkXShards(shards)
          return shards
  
      data_shards = get_xshards("x")
      pred_shards = get_xshards("prediction")
      result_shards = update_predict_xshards(data_shards, pred_shards)
      result = np.concatenate(
          [shard["prediction"] for shard in result_shards.collect()]
      )
      expected_result = np.concatenate(
          [shard["x"] for shard in result_shards.collect()]
      )
  
      assert np.array_equal(result, expected_result)
  
imports: from unittest import TestCase
  import os
  import pytest
  import numpy
  from pyspark.sql.types import ArrayType, DoubleType
  from zoo.orca import init_orca_context, stop_orca_context
  from zoo.orca.data import SparkXShards
  from zoo.orca.data.image.utils import chunks
  from zoo.orca.learn.utils import convert_predict_rdd_to_dataframe, _dataframe_to_xshards, convert_predict_xshards_to_dataframe, convert_predict_rdd_to_xshard, update_predict_xshards
label_desc: Use image node_id 7 for calling the TestUtil obj's underlying member method code with example usage: obj.test_update_predict_xshard() and returns: shards