code: private void branch(int stackAdjust, Location location, byte opcode) {
          if (!(location instanceof InstructionList.LabelInstruction)) {
              throw new IllegalArgumentException("Branch location is not a label instruction");
          }
          mInstructions.new BranchInstruction(stackAdjust, opcode,
                                              (InstructionList.LabelInstruction)location);
      }
docs: flow control instructions