Protobuf\Binary\StreamWriter::writeByteStream PHP Метод

    public function writeByteStream(Stream $stream, Stream $value)
    {
        $length = $value->getSize();
        $value->seek(0);
        $this->writeVarint($stream, $length);
        $stream->writeStream($value, $length);
    }

 /**
  * @dataProvider providerByteStream
  */
 public function testComputeByteStreamSize($value)
 {
     $stream = Stream::create();
     $this->writer->writeByteStream($stream, $value);
     $streamSize = $stream->getSize();
     $actualSize = $this->calculator->computeByteStreamSize($value);
     $this->assertEquals($streamSize, $actualSize);
 }