public function implode($glue = '', callable $callback = null)
    {
        return implode($glue, $callback ? array_map($callback, $this->items) : $this->items);
    }
public function implode($glue = '', callable $callback = null)
    {
        return implode($glue, $callback ? array_map($callback, $this->items) : $this->items);
    }
public function implode ( $ glue = '' , callable $ callback = null ) { return implode ( $ glue , $ callback ? array_map ( $ callback , $ this -> items ) : $ this -> items ) ; }
Implode the collection values.

@see implode()
@param string        $glue
@param callable|null $callback
@return string
Implode the collection values .