--- old/src/java.base/share/classes/java/lang/System.java	2018-12-06 17:52:48.821358551 -0500
+++ new/src/java.base/share/classes/java/lang/System.java	2018-12-06 17:52:48.649357699 -0500
@@ -970,7 +970,7 @@
         if (key == null) {
             throw new NullPointerException("key can't be null");
         }
-        if (key.equals("")) {
+        if (key.isEmpty()) {
             throw new IllegalArgumentException("key can't be empty");
         }
     }