Reverse sensor_clearsky_filter commented section

rdtools/analysis_chains.py

@@ -805,16 +805,15 @@ def _sensor_preprocess(self):
                 "poa_global must be available to perform _sensor_preprocess"
             )
 
-        # TODO: Ask Mike about this section
-        # if "sensor_clearsky_filter" in self.filter_params:
-        #     try:
-        #         if self.poa_global_clearsky is None:
-        #             self._calc_clearsky_poa(model="isotropic")
-        #     except AttributeError:
-        #         raise AttributeError(
-        #             "No poa_global_clearsky. 'set_clearsky' must be run "
-        #             + "to allow filter_params['sensor_clearsky_filter']. "
-        #         )
+        if "sensor_clearsky_filter" in self.filter_params:
+            try:
+                if self.poa_global_clearsky is None:
+                    self._calc_clearsky_poa(model="isotropic")
+            except AttributeError:
+                raise AttributeError(
+                    "No poa_global_clearsky. 'set_clearsky' must be run "
+                    + "to allow filter_params['sensor_clearsky_filter']. "
+                )
         if self.power_expected is None:
             # Thermal details required if power_expected is not manually set.
             if self.temperature_cell is None and self.temperature_ambient is None: