code: function coercePrimitiveToObject(obj) {
    if (isPrimitive(obj)) {
      obj = Object(obj);
    }
    // istanbul ignore next
    if (NO_KEYS_IN_STRING_OBJECTS && isString(obj)) {
      forceStringCoercion(obj);
    }
    return obj;
  }
docs: Make primtives types like strings into objects.