private void markDeadInstructions() { Set<Instruction> instructionSet = Sets.newHashSet(instructions); for (Instruction instruction : mutableInstructionList) { if (!instructionSet.contains(instruction)) { ((InstructionImpl) instruction).setMarkedAsDead(true); for (Instruction nextInstruction : instruction.getNextInstructions()) { nextInstruction.getPreviousInstructions().remove(instruction); } } } }