// dependency isn't enough to ensure the side effects take place
      // (b/185483669).
      if (!IsStatefulFunctionalControlFlowOp(defining_op)) {
        result.sinks.erase(defining_op);
      }
    }
    if (predecessors.empty() && (!has_in_island_operands ||
                                 IsStatefulFunctionalControlFlowOp(&sub_op))) {
      result.sources.insert(&sub_op);
    }
  }
  return result;
}