public function parseToken()
    {
        foreach ($this->chain as $parser) {
            if ($response = $parser->parse($this->request)) {
                return $response;
            }
        }
    }
public function parseToken()
    {
        foreach ($this->chain as $parser) {
            if ($response = $parser->parse($this->request)) {
                return $response;
            }
        }
    }
public function parseToken ( ) { foreach ( $ this -> chain as $ parser ) { if ( $ response = $ parser -> parse ( $ this -> request ) ) { return $ response ; } } }
Iterate through the parsers and attempt to retrieve
a value, otherwise return null.

@return string|null
Iterate through the parsers and attempt to retrieve a value otherwise return null .