js/utils/common.js
function mergeAsArray(destination, source, property) {
    destination[property] = source[property].concat(destination[property] || []);
}
function mergeAsArray(destination, source, property) {
    destination[property] = source[property].concat(destination[property] || []);
}
function mergeAsArray ( destination , source , property ) { destination [ property ] = source [ property ] . concat ( destination [ property ] || [ ] ) ; }
Merges arrays by concatenating them

@param {Object} destination
@param {Object} source
@param {String} property
Merges arrays by concatenating them