public function open($id)
    {
        if (null === $session = $this->get($id)) {
            $session = $this->children[] = new self(microtime(true) * 1000, $this->morePrecision);
        }

        return $session;
    }
public function open($id)
    {
        if (null === $session = $this->get($id)) {
            $session = $this->children[] = new self(microtime(true) * 1000, $this->morePrecision);
        }

        return $session;
    }
public function open ( $ id ) { if ( null === $ session = $ this -> get ( $ id ) ) { $ session = $ this -> children [ ] = new self ( microtime ( true ) * 1000 , $ this -> morePrecision ) ; } return $ session ; }
Creates or re-opens a child section.

@param string|null $id Null to create a new section, the identifier to re-open an existing one

@return self
Creates or re - opens a child section .