Автор: Fabio B. Silva (fabio.bat.silva@gmail.com)
Наследование: implements Protobuf\Binary\Platform\NegativeEncoder
 /**
  * @expectedException RuntimeException
  * @expectedExceptionMessage Negative integers are only supported with GMP or BC (64bit) intextensions.
  */
 public function testEncodeEncodeSFixed64Exception()
 {
     $encoder = new InvalidNegativeEncoder();
     $encoder->encodeSFixed64(-1);
 }