code: public static boolean couldBeSipMessage(final Buffer data) throws IOException {
          final byte a = data.getByte(0);
          final byte b = data.getByte(1);
          final byte c = data.getByte(2);
          return couldBeSipMessage(a, b, c);
      }
docs: Helper function that checks whether or not the data could be a SIP message. It is a very
  basic check but if it doesn't go through it definitely is not a SIP message.
  
  @param data
  @return