public function key($name): string {
        if ( ! isset($this->details[$name])) {
            throw new CryptographicDetailsDoNotContainKey($name);
        }
        return $this->details[$name];
    }
public function key($name): string {
        if ( ! isset($this->details[$name])) {
            throw new CryptographicDetailsDoNotContainKey($name);
        }
        return $this->details[$name];
    }
public function key ( $ name ) : string { if ( ! isset ( $ this -> details [ $ name ] ) ) { throw new CryptographicDetailsDoNotContainKey ( $ name ) ; } return $ this -> details [ $ name ] ; }
get the value for a key from the cryptographic details

@param $name
@return string
@throws CryptographicDetailsDoNotContainKey
get the value for a key from the cryptographic details