code: def test_resample_linear():
      df = pd.DataFrame(
          index=to_datetime(["2019-01-01", "2019-01-05", "2019-01-08"]),
          data={"label": ["a", "e", "j"], "y": [1.0, 5.0, 8.0]},
      )
      post_df = pp.resample(df=df, rule="1D", method="linear")
      """
                 label    y
      2019-01-01     a  1.0
      2019-01-02   NaN  2.0
      2019-01-03   NaN  3.0
      2019-01-04   NaN  4.0
      2019-01-05     e  5.0
      2019-01-06   NaN  6.0
      2019-01-07   NaN  7.0
      2019-01-08     j  8.0
      """
      assert post_df.equals(
          pd.DataFrame(
              index=pd.to_datetime(
                  [
                      "2019-01-01",
                      "2019-01-02",
                      "2019-01-03",
                      "2019-01-04",
                      "2019-01-05",
                      "2019-01-06",
                      "2019-01-07",
                      "2019-01-08",
                  ]
              ),
              data={
                  "label": [
                      "a",
                      np.NaN,
                      np.NaN,
                      np.NaN,
                      "e",
                      np.NaN,
                      np.NaN,
                      "j",
                  ],
                  "y": [1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0],
              },
          )
      )
  
file_path: superset/tests/unit_tests/pandas_postprocessing/test_resample.py
imports: import numpy
  import pandas
  import pytest
  from pandas import to_datetime
  from superset.exceptions import InvalidPostProcessingError
  from superset.utils import pandas_postprocessing
  from tests.unit_tests.fixtures.dataframes import categories_df, timeseries_df
label_desc: Use image node_id 6 for calling a global function with example usage: test_resample_linear() without return types