public Boolean execute(ComplexEvent event) {
        Object left = leftExpressionExecutor.execute(event);
        Object right = rightExpressionExecutor.execute(event);
        return left == null || right == null || execute(left, right);
    }
Parent Executor class for Not Equal condition. Data type specific sub classes will extend this.
modules/siddhi-core/src/main/java/io/siddhi/core/executor/condition/compare/notequal/NotEqualCompareConditionExpressionExecutor.java