code: function shallowCopy(src, dst) {
    if (isArray(src)) {
      dst = dst || [];
  
      for (var i = 0, ii = src.length; i < ii; i++) {
        dst[i] = src[i];
      }
    } else if (isObject(src)) {
      dst = dst || {};
  
      for (var key in src) {
        if (!(key.charAt(0) === '$' && key.charAt(1) === '$')) {
          dst[key] = src[key];
        }
      }
    }
  
    return dst || src;
  }
docs: Creates a shallow copy of an object, an array or a primitive.
  
  Assumes that there are no proto properties for objects.