docstr: Test filling in missing entries of a series.
docstr_tok: ["Test","filling","in","missing","entries","of","a","series","."]
code: def test_regularize_series(self, datetimes, expected):
      """Test filling in missing entries of a series."""
      dt_idx = pd.to_datetime(datetimes)
      test_series = pd.DataFrame(
          np.arange(len(dt_idx)), index=dt_idx, columns=["value"]
      ).sort_index()
      regularized_series = regularization.regularize_series(test_series)
      self.assertTrue(regularized_series.equals(expected))
  
file_path: probability/tensorflow_probability/python/sts/regularization_test.py
imports: import datetime
  from absl.testing import parameterized
  import numpy
  import pandas
  from tensorflow_probability.python.internal import test_util
  from tensorflow_probability.python.sts import regularization
label_desc: Use image node_id 1 for calling the RegularizationTest obj's underlying member method code with example usage: obj.test_regularize_series(datetimes, expected) without return types