dist/scripts/vendor.min.js
function defaults(dst, src) {
  forEach(src, function(value, key) {
    if (!isDefined(dst[key])) {
      dst[key] = value;
    }
  });
}
function defaults(dst, src) {
  forEach(src, function(value, key) {
    if (!isDefined(dst[key])) {
      dst[key] = value;
    }
  });
}
shallow copy over values from `src` that are not already specified on `dst`