Adding empty line at the end of file.

Author: ppisl

graalpython/lib-graalpython/itertools.py

@@ -486,4 +486,4 @@ def _grouper(self, tgtkey):
         while self._currkey == tgtkey:
             yield self._currvalue
             self._currvalue = next(self._iter) # Exit on StopIteration
-            self._currkey = self._keyfunc(self._currvalue)
+            self._currkey = self._keyfunc(self._currvalue)