How do we make multi lines string in cloud code ?

I'm trying to build a mongodb $where clause like this:

var whereQuery = "function () {
    for (var index in this.relations) {
        var current = this.relations[index];
        if (current._id == 2) { 
            return true; 
        } 
    } 
    return false;
}";

This give me a "sun.org.mozilla.javascript.internal.EvaluatorException: unterminated string literal (#192)" on the first line.

If it is not possible, is there another way to do this? Or do I really need to build the entire $where expression on one line?

Great! 

Thanks.