@Override
    public DateTimeExpression<T> as(Path<T> alias) {
        return Expressions.dateTimeOperation(getType(), Ops.ALIAS, mixin, alias);
    }
Create an expression representing the current time instant as a DateTimeExpression instance

@return current timestamp
querydsl-core/src/main/java/com/querydsl/core/types/dsl/DateTimeExpression.java