src/share/classes/jdk/internal/org/objectweb/asm/tree/analysis/Frame.java

@@ -752,16 +752,16 @@
      *
      * @return a string representation of this frame.
      */
     @Override
     public String toString() {
-        StringBuffer b = new StringBuffer();
+        StringBuilder sb = new StringBuilder();
         for (int i = 0; i < getLocals(); ++i) {
-            b.append(getLocal(i));
+            sb.append(getLocal(i));
         }
-        b.append(' ');
+        sb.append(' ');
         for (int i = 0; i < getStackSize(); ++i) {
-            b.append(getStack(i).toString());
+            sb.append(getStack(i).toString());
         }
-        return b.toString();
+        return sb.toString();
     }
 }