protected function generateFromPsr7Request(Psr7Request $request) : string
    {
        $id = isset($this->request->getHeader('X-SIGNED-ID')[0]) ?
            $this->request->getHeader('X-SIGNED-ID')[0] : '';
        $timestamp = isset($this->request->getHeader('X-SIGNED-TIMESTAMP')[0]) ?
            $this->request->getHeader('X-SIGNED-TIMESTAMP')[0] : '';

        return $this->generate(
            (string) $id,
            (string) $this->request->getMethod(),
            (string) $timestamp,
            (string) $this->request->getUri(),
            (string) $this->request->getBody()
        );
    }