--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java	Mon Nov 11 17:43:10 2019 -0800
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java	Tue Nov 12 06:32:13 2019 +0000
@@ -1467,7 +1467,6 @@
             // check that there are no duplicate case labels or default clauses.
             Set<Object> labels = new HashSet<>(); // The set of case labels.
             boolean hasDefault = false;      // Is there a default label?
-            @SuppressWarnings("preview")
             CaseTree.CaseKind caseKind = null;
             boolean wasError = false;
             for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {