src/jdk.compiler/share/classes/com/sun/tools/javac/comp/CaptureScanner.java

@@ -90,10 +90,14 @@
      }
  
      /**
       * Obtains the list of captured local variables in the tree under analysis.
       */
-     List<Symbol.VarSymbol> analyzeCaptures() {
+     public List<Symbol.VarSymbol> analyzeCaptures() {
          scan(tree);
          return List.from(fvs);
      }
+ 
+     public boolean isVarSeen(VarSymbol s) {
+         return seenVars.contains(s);
+     }
  }