src/ItemCollectors/RouterGlobalsCollector.php
public function callback(string $name, callable $callback): self
    {
        $this->data->callback($name, $callback);
        return $this;
    }
public function callback(string $name, callable $callback): self
    {
        $this->data->callback($name, $callback);
        return $this;
    }
public function callback ( string $ name , callable $ callback ) : self { $ this -> data -> callback ( $ name , $ callback ) ; return $ this ; }
Defines a global callback

@param   string $name The name of the callback
@param   callable $callback A callback

@return  $this
Defines a global callback