fixing filter function test
@@ -385,5 +385,6 @@ def test_hooks(mix_and_sources, check_against_regression_data):
def test_filter_function_pass():
# this test is for 100% coverage
- function = effects.FilterFunction
- function.func()
+ function = effects.FilterFunction()
+ dummy_item = None
+ function.func(dummy_item)
