code: def test_pandas_pandas():
      input_data = pd.DataFrame({"x": [1, 2, 3]})
      expected_output = input_data
      actual_output = _convert_batch_type_to_pandas(input_data)
      pd.testing.assert_frame_equal(expected_output, actual_output)
  
      actual_output = _convert_pandas_to_batch_type(
          actual_output, type=BatchFormat.PANDAS
      )
      pd.testing.assert_frame_equal(actual_output, input_data)
  
imports: import pytest
  import warnings
  import pandas
  import numpy
  import pyarrow
  from ray.air._internal.torch_utils import convert_ndarray_to_torch_tensor
  from ray.air.constants import TENSOR_COLUMN_NAME
  from ray.air.util.data_batch_conversion import _convert_batch_type_to_pandas, _convert_pandas_to_batch_type, _convert_batch_type_to_numpy, _cast_ndarray_columns_to_tensor_extension, _cast_tensor_columns_to_ndarrays
  from ray.air.util.data_batch_conversion import BatchFormat
  from ray.air.util.tensor_extensions.pandas import TensorArray
  from ray.air.util.tensor_extensions.arrow import ArrowTensorArray
label_desc: Use image node_id 1 for calling a global function with example usage: test_pandas_pandas() without return types