Masonry.prototype._getMeasurement = function(measurement, size) {
var option = this.options[measurement];
var elem;
if (!option) {
this[measurement] = 0;
} else if (typeof option === 'function') {
this[measurement] = option.call(this);
} else {
if (typeof option === 'string') {
elem = this.element.querySelector(option);
} else if (isElement(option)) {
elem = option;
}
this[measurement] = elem ? getSize(elem)[size] : option;
}
};