code: def test_iteration(self):
      index = period_range(start="1/1/10", periods=4, freq="B")
  
      result = list(index)
      assert isinstance(result[0], Period)
      assert result[0].freq == index.freq
  
file_path: pandas/pandas/tests/indexes/period/test_period.py
imports: import numpy
  import pytest
  from pandas import Index, NaT, Period, PeriodIndex, Series, date_range, offsets, period_range
  import pandas._testing
label_desc: Use image node_id 8 for calling the TestPeriodIndex obj's underlying member method code with example usage: obj.test_iteration() without return types