Fix "ReturnValueIgnored" errors flagged by error-prone

Author: kluever

src/test/java/junit/tests/framework/AssertTest.java

@@ -82,15 +82,15 @@ public void testAssertStringNotEqualsNull() {
             assertEquals("foo", null);
             fail();
         } catch (ComparisonFailure e) {
-            e.getMessage(); // why no assertion?
+            String unused = e.getMessage(); // why no assertion?
         }
     }
 
     public void testAssertNullNotEqualsNull() {
         try {
             assertEquals(null, new Object());
         } catch (AssertionFailedError e) {
-            e.getMessage(); // why no assertion?
+            String unused = e.getMessage(); // why no assertion?
             return;
         }
         fail();
@@ -168,4 +168,4 @@ public void testAssertNotSameFailsNull() {
         }
         fail();
     }
-}
+}