protected function getEmptyBody()
    {
        $body = $this->response->getBody();
        if (!$body->isWritable()) {
            throw new \RuntimeException('response body is not writeble');
        }
        if ($body->getSize() !== 0) {
            throw new \RuntimeException('response body is not empty');
        }

        return $body;
    }
protected function getEmptyBody()
    {
        $body = $this->response->getBody();
        if (!$body->isWritable()) {
            throw new \RuntimeException('response body is not writeble');
        }
        if ($body->getSize() !== 0) {
            throw new \RuntimeException('response body is not empty');
        }

        return $body;
    }
protected function getEmptyBody ( ) { $ body = $ this -> response -> getBody ( ) ; if ( ! $ body -> isWritable ( ) ) { throw new \ RuntimeException ( 'response body is not writeble' ) ; } if ( $ body -> getSize ( ) !== 0 ) { throw new \ RuntimeException ( 'response body is not empty' ) ; } return $ body ; }
ensure body is empty and writable and return that

@return \Psr\Http\Message\StreamInterface
@throws \RuntimeException
ensure body is empty and writable and return that