code: def test_spark_df_to_shards(self):
      file_path = os.path.join(self.resource_path, "orca/data/csv")
      from pyspark.sql import SparkSession
  
      spark = (
          SparkSession.builder.master("local[1]")
          .appName("test_spark_backend")
          .config("spark.driver.memory", "6g")
          .getOrCreate()
      )
      df = spark.read.csv(file_path)
      data_shards = spark_df_to_pd_sparkxshards(df)
  
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 14 for calling the TestSparkXShards obj's underlying member method code with example usage: obj.test_spark_df_to_shards() without return types