docs: function fetch() {
    for (var _len = arguments.length, options = Array(_len), _key = 0; _key < _len; _key++) {
      options[_key] = arguments[_key];
    }
  
    switch (options.length) {
      case 0:
        fetchBy.call(this);
        break;
      case 1:
        if (typeof options[0] === "function") {
          fetchBy.call(this, [this.primaryKey], options[0]);
        } else if (Array.isArray(options[0])) {
          fetchBy.call(this, options[0]);
        } else {
          fetchBy.call(this, [options[0]]);
        }
        break;
      case 2:
        if (Array.isArray(options[0])) {
          fetchBy.call(this, options[0], options[1]);
        } else {
          fetchBy.call(this, [options[0]], options[1]);
        }
        break;
    }
  }