public function getProtectedHeaderParameter(string $key)
    {
        if ($this->hasProtectedHeaderParameter($key)) {
            return $this->getProtectedHeader()[$key];
        }

        throw new \InvalidArgumentException(\sprintf('The protected header "%s" does not exist', $key));
    }
public function getProtectedHeaderParameter(string $key)
    {
        if ($this->hasProtectedHeaderParameter($key)) {
            return $this->getProtectedHeader()[$key];
        }

        throw new \InvalidArgumentException(\sprintf('The protected header "%s" does not exist', $key));
    }
public function getProtectedHeaderParameter ( string $ key ) { if ( $ this -> hasProtectedHeaderParameter ( $ key ) ) { return $ this -> getProtectedHeader ( ) [ $ key ] ; } throw new \ InvalidArgumentException ( \ sprintf ( 'The protected header "%s" does not exist' , $ key ) ) ; }
Returns the value of the protected header of the specified key.

@param string $key The key

@return mixed|null Header value
Returns the value of the protected header of the specified key .