Inheritance

var LocationQuery = function() {
    this.projects = null;
    this.parameters = null;
    this.labels = null;
    this.gpsBounds = null;
    this.pageObject = null;
    this.query = {};
};

LocationQuery.prototype._addToQuery = function(prop) {
    if (!!this[prop]) {
        this.query[prop] = this[prop];
    }
};

LocationQuery.prototype.toParam = function() {
    var props = ["projects", "parameters", "labels", "gpsBounds", "locationIds", "pageObject"];
    props.map(this._addToQuery, this);
    var val = JSON.stringify(this.query);

    return {
        q: val
    };
};

var LocationDataQuery = function() {
    this.resolution = null;
    this.timeslice = null;
};

// Inherit from LocationQuery
LocationDataQuery.prototype = Object.create(new LocationQuery());

LocationDataQuery.prototype.toParam = function() {
    // Add locationSpecific properties to query
    var locationDataProps = ["resolution", "timeslice"];
    locationDataProps.map(this._addToQuery, this);
    
    // Add super values and return result
    return LocationQuery.prototype.toParam.call(this);
};