code: def test_find_missing_dates():
      """Tests find_missing_dates function"""
      timestamp_series = pd.Series(
          [
              datetime.datetime(2018, 1, 1, 0, 0, 1),
              datetime.datetime(2018, 1, 1, 0, 0, 2),
              datetime.datetime(2018, 1, 1, 0, 0, 10),
              datetime.datetime(2018, 1, 1, 0, 0, 4),
          ]
      )
  
      gaps = find_missing_dates(timestamp_series)
      expected_gaps = pd.DataFrame(
          {
              "right_before_gap": pd.Series(
                  [
                      datetime.datetime(2018, 1, 1, 0, 0, 2),
                      datetime.datetime(2018, 1, 1, 0, 0, 4),
                  ]
              ),
              "right_after_gap": pd.Series(
                  [
                      datetime.datetime(2018, 1, 1, 0, 0, 4),
                      datetime.datetime(2018, 1, 1, 0, 0, 10),
                  ]
              ),
              "gap_size": [1.0, 5.0],
          }
      )
      assert gaps.equals(expected_gaps)
  
imports: import datetime
  import numpy
  import pandas
  import pytest
  from greykite.common.constants import ADJUSTMENT_DELTA_COL
  from greykite.common.constants import END_TIME_COL
  from greykite.common.constants import METRIC_COL
  from greykite.common.constants import START_TIME_COL
  from greykite.common.constants import TIME_COL
  from greykite.common.constants import VALUE_COL
  from greykite.common.data_loader import DataLoader
  from greykite.common.enums import TimeEnum
  from greykite.common.python_utils import assert_equal
  from greykite.common.testing_utils import generate_df_with_reg_for_tests
  from greykite.common.time_properties import describe_timeseries
  from greykite.common.time_properties import fill_missing_dates
  from greykite.common.time_properties import find_missing_dates
  from greykite.common.time_properties import get_canonical_data
  from greykite.common.time_properties import infer_freq
  from greykite.common.time_properties import min_gap_in_seconds
label_desc: Use image node_id 3 for calling a global function with example usage: test_find_missing_dates() without return types