private void addBackwardTrace(@NotNull InstructionKey fromKey, @NotNull InstructionKey nextKey) {
      if (fromKey.getOffset() >= 0 && nextKey.getOffset() < myInstructions.size()) {
        InstructionState state = myStates.get(nextKey);
        if (state == null) myStates.put(nextKey, state = new InstructionState(nextKey));
        state.addBackwardTrace(fromKey);
      }
    }
private void addBackwardTrace(@NotNull InstructionKey fromKey, @NotNull InstructionKey nextKey)