code: def test_period_ordinal_start_values(freq, expected):
      # information for Jan. 1, 1970.
      assert (
          period_ordinal(1970, 1, 1, 0, 0, 0, 0, 0, get_freq_code(freq))
          == expected
      )
  
file_path: pandas/pandas/tests/tslibs/test_period.py
imports: import numpy
  import pytest
  from pandas._libs.tslibs import iNaT, to_offset
  from pandas._libs.tslibs.period import extract_ordinals, get_period_field_arr, period_asfreq, period_ordinal
  import pandas._testing
label_desc: Use image node_id 3 for calling a global function with example usage: test_period_ordinal_start_values(freq, expected) without return types