#vulnerable code 
                                public boolean enableDebugSupport(final int port, final boolean waitForConnection) {
        V8.checkDebugThread();
        debugEnabled = enableDebugSupport(getHandle(), port, waitForConnection);
        return debugEnabled;
    } 
                            #location 3 
                            #vulnerability type THREAD_SAFETY_VIOLATION
#fixed code
                                public boolean enableDebugSupport(final int port, final boolean waitForConnection) {
        V8.checkDebugThread();
        debugEnabled = enableDebugSupport(getV8RuntimePtr(), port, waitForConnection);
        return debugEnabled;
    }