public static TestCallback addStreamCallback(SiddhiAppRuntime siddhiAppRuntime, String streamName,
                                                 Object[]... expected) {

        TestStreamCallback callBack = new TestStreamCallback(expected);
        siddhiAppRuntime.addCallback(streamName, callBack);
        return callBack;
    }
Add a callback to the given {@link SiddhiAppRuntime} and validate the assertions.

@param siddhiAppRuntime the SiddhiAppRuntime
@param streamName       the stream
@param expected         expected event data
@return TestCallback
modules/siddhi-core/src/test/java/io/siddhi/core/TestUtil.java