function copy(val, key) {
  if (key === '__proto__') {
    return;
  }

  var obj = this[key];
  if (isObject(val) && isObject(obj)) {
    mixinDeep(obj, val);
  } else {
    this[key] = val;
  }
}
The product receives input or data, but it does
        not validate or incorrectly validates that the input has the
        properties that are required to process the data safely and
        correctly.