code: def test_to_timestamp_freq(self):
      idx = period_range("2017", periods=12, freq="Y-DEC")
      result = idx.to_timestamp()
      expected = date_range("2017", periods=12, freq="YS-JAN")
      tm.assert_index_equal(result, expected)
  
file_path: pandas/pandas/tests/indexes/period/methods/test_to_timestamp.py
imports: from datetime import datetime
  import numpy
  import pytest
  from pandas import DatetimeIndex, NaT, PeriodIndex, Timedelta, Timestamp, date_range, period_range
  import pandas._testing
label_desc: Use image node_id 2 for calling the TestToTimestamp obj's underlying member method code with example usage: obj.test_to_timestamp_freq() without return types