code: def test_load_hourly_parking():
      dl = DataLoader()
      df = dl.load_parking(system_code_number=None)
      assert list(df.columns) == [
          "LastUpdated",
          "Capacity",
          "Occupancy",
          "OccupancyRatio",
      ]
      assert df.shape == (1328, 4)
  
      df = dl.load_parking(system_code_number="NIA South")
      assert list(df.columns) == [
          "SystemCodeNumber",
          "Capacity",
          "Occupancy",
          "LastUpdated",
          "OccupancyRatio",
      ]
      assert df.shape == (1204, 5)
  
imports: import os
  import re
  import pandas
  import pytest
  from greykite.common.constants import TIME_COL
  from greykite.common.data_loader import DataLoader
  from greykite.common.testing_utils import assert_equal
label_desc: Use image node_id 8 for calling a global function with example usage: test_load_hourly_parking() without return types