code: private void extractInstructions(InstructionGroup group) {
          for (InstructionGraphNode node : group.getNodes()) {
              if (node != group.getRoot()) {
                  AbstractInsnNode insn = node.getInstruction();
                  method.instructions.remove(insn);
                  group.getInstructions().add(insn);
              }
          }
      }
docs: move all group instructions except for the root from the underlying method into the groups Insnlist