@Override
      public void visitInstruction(Instruction instruction, int offset, int nextOffset) {
        if (nextOffset > flow.getSize()) nextOffset = flow.getSize();

        boolean unassigned = isLeaf(nextOffset) || maybeUnassigned[nextOffset];
        maybeUnassigned[offset] |= unassigned;
      }
@Override
      public void visitInstruction(Instruction instruction, int offset, int nextOffset)