code: def test_max_values(self):
      file_path = os.path.join(
          self.resource_path, "orca/data/csv/morgage1.csv"
      )
      data_shard = bigdl.orca.data.pandas.read_csv(file_path)
      max_value = data_shard.max_values("sale_price")
      assert max_value == 475000, "max value of sale_price should be 2"
  
imports: import os.path
  import pytest
  from unittest import TestCase
  import bigdl.orca.data
  import bigdl.orca.data.pandas
  from bigdl.orca.data import SharedValue
  from bigdl.dllib.nncontext import *
  from bigdl.orca.data.transformer import *
  from bigdl.orca import init_orca_context
label_desc: Use image node_id 17 for calling the TestSparkXShards obj's underlying member method code with example usage: obj.test_max_values() without return types