Protobuf\Binary\StreamWriter::writeFixed64 PHP Method

    public function writeFixed64(Stream $stream, $value)
    {
        $bytes = pack('V*', $value & 0xffffffff, $value / (0xffffffff + 1));
        $this->writeBytes($stream, $bytes, 8);
    }

 /**
  * @dataProvider providerFixed64
  */
 public function testComputeFixed64Size($value)
 {
     $stream = Stream::create();
     $this->writer->writeFixed64($stream, $value);
     $streamSize = $stream->getSize();
     $actualSize = $this->calculator->computeFixed64Size($value);
     $this->assertEquals($streamSize, $actualSize);
 }