code: def test_load_tsf_to_dataframe(input_path, return_type, output_df):
      """Test function for loading tsf format."""
      data_path = os.path.join(
          os.path.dirname(sktime.__file__),
          input_path,
      )
  
      expected_metadata = {
          "frequency": "yearly",
          "forecast_horizon": 4,
          "contain_missing_values": False,
          "contain_equal_length": False,
      }
  
      df, metadata = load_tsf_to_dataframe(
          data_path, return_type=return_type
      )
  
      assert_frame_equal(df, output_df, check_dtype=False)
      assert metadata == expected_metadata
      if return_type != "default_tsf":
          assert check_is_mtype(
              obj=df, mtype=return_type, msg_return_dict="list"
          )
  
imports: import os
  import tempfile
  import numpy
  import pandas
  import pytest
  from pandas._testing import assert_frame_equal
  import sktime
  from sktime.datasets import generate_example_long_table, load_from_long_to_dataframe, load_from_tsfile, load_from_tsfile_to_dataframe, load_tsf_to_dataframe, write_dataframe_to_tsfile, write_panel_to_tsfile
  from sktime.datasets._data_io import MODULE, _load_provided_dataset
  from sktime.datasets._readers_writers.tsf import _convert_tsf_to_hierarchical
  from sktime.datatypes import check_is_mtype
label_desc: Use image node_id 5 for calling a global function with example usage: test_load_tsf_to_dataframe(input_path, return_type, output_df) without return types