code: public static void expectSIP2_0(final Buffer buffer) throws SipParseException {
          expect(buffer, 'S');
          expect(buffer, 'I');
          expect(buffer, 'P');
          expect(buffer, '/');
          expect(buffer, '2');
          expect(buffer, '.');
          expect(buffer, '0');
      }
docs: Expect that the next set of bytes is "SIP/2.0" and if not then we will
  throw a {@link SipParseException}
  
  @param buffer