code: def test_dtype(self):
      file_path = os.path.join(self.resource_path, "orca/data/csv")
      data_shard = bigdl.orca.data.pandas.read_csv(
          file_path, dtype="float"
      )
      data = data_shard.collect()
      df = data[0]
      assert df.location.dtype == "float64"
      assert df.ID.dtype == "float64"
      data_shard = bigdl.orca.data.pandas.read_csv(
          file_path, dtype={"sale_price": np.float32, "ID": np.int64}
      )
      data = data_shard.collect()
      df2 = data[0]
      assert (
          df2.sale_price.dtype == "float32" and df2.ID.dtype == "int64"
      )
  
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 20 for calling the TestSparkXShards obj's underlying member method code with example usage: obj.test_dtype() without return types