original_string: public function only($key)
      {
          $keys = is_array($key) ? $key : func_get_args();
  
          return new static($this->classname, $this->filterByKeys($keys));
      }
code: public function only($key)
      {
          $keys = is_array($key) ? $key : func_get_args();
  
          return new static($this->classname, $this->filterByKeys($keys));
      }
code_tokens: public function only ( $ key ) { $ keys = is_array ( $ key ) ? $ key : func_get_args ( ) ; return new static ( $ this -> classname , $ this -> filterByKeys ( $ keys ) ) ; }
docstring: Get all items with the specified keys.
  
  @param mixed $key
  
  @return static
docstring_tokens: Get all items with the specified keys .