code: def test_delta_rdef(self):
      self.generate(
          "test_delta_Rdef",
          "test_lowess_delta.csv",
          out="out_Rdef",
          kwargs=lambda data: {
              "frac": 0.1,
              "delta": 0.01 * np.ptp(data["x"]),
          },
      )
  
imports: import os
  import numpy
  from numpy.testing import assert_, assert_allclose, assert_almost_equal, assert_equal, assert_raises
  import pytest
  from statsmodels.nonparametric.smoothers_lowess import lowess
  import pandas
label_desc: Use image node_id 11 for calling the TestLowess obj's underlying member method code with example usage: obj.test_delta_rdef() without return types