code: public function whateverMatches(string $param) : RouteBuilder
      {
          if (array_key_exists($param, $this->matchers)) {
              unset($this->matchers[$param]);
          }
  
          return $this;
      }
docs: Returns a route having removed all formerly set matchers
  for the param with given name.
  
  @param string $param The name of the param all matchers should be removed for
  @return RouteBuilder