public void removeFunctionListener(SAFunctionListener functionListener) {
        if (mFunctionListener != null && functionListener != null) {
            mFunctionListener.remove(functionListener);
        }
    }
@Test
    public void removeFunctionListener() {
        SensorsDataAPI sensorsDataAPI = SAHelper.initSensors(mApplication);
        SAFunctionListener listener = new SAFunctionListener() {
            @Override
            public void call(String function, JSONObject args) {
                Assert.fail();
            }
        };
        sensorsDataAPI.addFunctionListener(listener);
        sensorsDataAPI.removeFunctionListener(listener);
        sensorsDataAPI.track("AppTest");
    }