#vulnerable code 
                                @Test
    @Ignore
    public void testAndroid() throws Exception {
        GCMWrapper gcmWrapper = new GCMWrapper(null, null);
        gcmWrapper.send(new AndroidGCMMessage("", Priority.normal, "yo!!!", 1), null, null);
    } 
                            #location 4 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Test
    @Ignore
    public void testAndroid() throws Exception {
        when(props.getProperty("gcm.api.key")).thenReturn("");
        when(props.getProperty("gcm.server")).thenReturn("");
        GCMWrapper gcmWrapper = new GCMWrapper(props, client);
        gcmWrapper.send(new AndroidGCMMessage("", Priority.normal, "yo!!!", 1), null, null);
        Thread.sleep(5000);
    }