in src/common/builder.js [104:119]
function recursiveMerge (target, src) {
for (var prop in src) {
if (Object.prototype.hasOwnProperty.call(src, prop)) {
if (target.prototype && target.prototype.constructor === target) {
// If the target object is a constructor override off prototype.
clobber(target.prototype, prop, src[prop]);
} else {
if (typeof src[prop] === 'object' && typeof target[prop] === 'object') {
recursiveMerge(target[prop], src[prop]);
} else {
clobber(target, prop, src[prop]);
}
}
}
}
}