code: def freq(self, request):
      return request.param
  
file_path: pandas/pandas/tests/indexes/datetimelike_/test_drop_duplicates.py
imports: import numpy
  import pytest
  from pandas import PeriodIndex, Series, date_range, period_range, timedelta_range
  import pandas._testing
label_desc: Use image node_id 1 for calling the TestDropDuplicatesPeriodIndex obj's underlying member method code with example usage: obj.freq(request) and returns: request