code: private int mergeOpcodes(int... opcodes) {
          int opcodesLen = opcodes.length;
          Assert.check(opcodesLen == 1 || opcodesLen == 2);
          return (opcodesLen == 1) ?
                  opcodes[0] :
                  ((opcodes[0] << ByteCodes.preShift) | opcodes[1]);
      }
docs: Fold two opcodes in a single int value (if required).