@Override
    protected StateFactory init(ExpressionExecutor[] attributeExpressionExecutors, ConfigReader configReader,
                                SiddhiQueryContext siddhiQueryContext) {
        //will not be called.
        return null;
    }
Implementation of {@link WindowProcessor} which represent a Window operating based on a expression.
modules/siddhi-core/src/main/java/io/siddhi/core/query/processor/stream/window/ExpressionWindowProcessor.java