Add alt fields and extend the docstring.

fuse/plugins/processing/corrected_areas.py

@@ -8,8 +8,14 @@
 class CorrectedAreasMC(straxen.CorrectedAreas):
     """Corrected areas plugin for MC data.
 
-    This plugin overwrites the cs1 and cs2 fields with the not-time-
-    corrected values as the effects are not simulated in the MC.
+    This plugin overwrites the (alt_)cs1 and (alt_)cs2 fields with the
+    not-time- corrected values as the effects of time dependent single-
+    electron gain, extraction efficiency and photo ionization are not
+    simulated in fuse.
+
+    Applying corrections for these effects to simulated data would lead
+    to incorrect results. This plugins should only be used for simulated
+    data!
     """
 
     __version__ = "0.0.1"
@@ -20,4 +26,7 @@ def compute(self, events):
         result["cs1"] = result["cs1_wo_timecorr"]
         result["cs2"] = result["cs2_wo_timecorr"]
 
+        result["alt_cs1"] = result["alt_cs1_wo_timecorr"]
+        result["alt_cs2"] = result["alt_cs2_wo_timecorr"]
+
         return result