diff --git a/mlair/data_handler/data_handler_mixed_sampling.py b/mlair/data_handler/data_handler_mixed_sampling.py
index 3e625ec7896f9637ce877d18b5fbe45fc4ca3973..2a3385e54ce36b025099e720779a7f8f49dd2e1e 100644
--- a/mlair/data_handler/data_handler_mixed_sampling.py
+++ b/mlair/data_handler/data_handler_mixed_sampling.py
@@ -357,13 +357,6 @@ class DataHandlerSeparationOfScalesSingleStation(DataHandlerMixedSamplingWithKzF
         self.history = self.stride(data, dim_name_of_shift, window, offset=self.window_history_offset)
 
     def stride(self, data: xr.DataArray, dim: str, window: int, offset: int = 0) -> xr.DataArray:
-
-        # this is just a code snippet to check the results of the kz filter
-        # import matplotlib
-        # matplotlib.use("TkAgg")
-        # import matplotlib.pyplot as plt
-        # xr.concat(res, dim="filter").sel({"variables":"temp", "Stations":"DEBW107", "datetime":"2010-01-01T00:00:00"}).plot.line(hue="filter")
-
         time_deltas = np.round(self.time_delta(self.cutoff_period)).astype(int)
         start, end = window, 1
         res = []
diff --git a/test/test_data_handler/test_data_handler_mixed_sampling.py b/test/test_data_handler/test_data_handler_mixed_sampling.py
index 5fedeebbeb6442a212545bef09b63603f38fa3f7..77b5d280f37520cee66f686b81886a77a216ab17 100644
--- a/test/test_data_handler/test_data_handler_mixed_sampling.py
+++ b/test/test_data_handler/test_data_handler_mixed_sampling.py
@@ -213,11 +213,18 @@ class TestDataHandlerSeparationOfScales:
         assert obj.data_handler_transformation.__qualname__ == DataHandlerSeparationOfScalesSingleStation.__qualname__
 
     def test_requirements(self):
-        obj = object.__new__(DataHandlerMixedSamplingWithKzFilter)
-        req1 = object.__new__(DataHandlerMixedSamplingWithFilterSingleStation)
-        req2 = object.__new__(DataHandlerKzFilterSingleStation)
-        req = list(set(req1.requirements() + req2.requirements()))
-        assert sorted(obj._requirements) == sorted(remove_items(req, "station"))
+        reqs = get_all_args(DefaultDataHandler)
+        obj = object.__new__(DataHandlerSeparationOfScales)
+        assert sorted(obj.own_args()) == reqs
+
+        reqs = get_all_args(DataHandlerSeparationOfScalesSingleStation, DataHandlerKzFilterSingleStation,
+                            DataHandlerMixedSamplingWithKzFilterSingleStation,DataHandlerFilterSingleStation,
+                            DataHandlerSingleStation, remove=["self", "id_class"])
+        assert sorted(obj._requirements) == reqs
+        reqs = get_all_args(DataHandlerSeparationOfScalesSingleStation, DataHandlerKzFilterSingleStation,
+                            DataHandlerMixedSamplingWithKzFilterSingleStation,DataHandlerFilterSingleStation,
+                            DataHandlerSingleStation, DefaultDataHandler, remove=["self", "id_class"])
+        assert sorted(obj.requirements()) == reqs
 
 
 class TestDataHandlerSeparationOfScalesSingleStation: