Add draft test.

Author: JoeZiminski

src/spikeinterface/preprocessing/saturation_working/test_saturation.py

@@ -0,0 +1,20 @@
+from spikeinterface.core.numpyextractors import NumpyRecording
+import numpy as np
+
+sample_frequency = 30_000
+sat_value = 5
+data = np.random.uniform(low=-0.5, high=0.5, size=(150000, 384))
+
+# chunk 1s so some start stops cut across a chunk
+# TODO: cut across segments
+starts_stops = [(0, 1000), (29000, 31000), (45123, 46234), (14950, 150001)]  # test behaviour over edge of data
+channel_range = slice(5, 100)
+
+for start, stop in starts_stops:
+    data[start:stop, channel_range] = sat_value
+
+recording = NumpyRecording([data] * 3, sample_frequency)  # TODO: all segments the same for now
+
+# pass recording to new function
+# check start, stops, channels match
+