text: import pytest
  
  from src.frequency import Frequency
  from src.frequency_filter import (FilterFactory, GammaFilter, BetaFilter,
                                    AlphaFilter, ThetaFilter, DeltaFilter)
  
  
  @pytest.mark.parametrize("test_input,expected,low,high", [
      (FilterFactory(Frequency.GAMMA), GammaFilter, 35, 70),
      (FilterFactory(Frequency.BETA), BetaFilter, 12, 35),
      (FilterFactory(Frequency.ALPHA), AlphaFilter, 8, 12),
      (FilterFactory(Frequency.THETA), ThetaFilter, 4, 8),
      (FilterFactory(Frequency.DELTA), DeltaFilter, 0.5, 4),
  ])
  def test_filter_factory_gamma(test_input, expected, low, high):
      filter_object = test_input.get_filter(50)
      assert isinstance(filter_object, expected)
      assert filter_object.low == low
      assert filter_object.high == high
  