Migrate to the reducer protocol style

[StanMGuo]

We are preparing to slowly and incrementally migrate our project from an existing TCA to the reducer protocol style. The migration guide shows how to start from the leaf node then move to a higher reducer then reach the root.

Since we have a great number of reducers, we try to find a way to update those reducers faster than starting from the leaf node one by one. For example, there is a parentAReducer combined with childBReducer, childCReducer and childDReducer. The childBReducer has migrated to the new reducer protocol style. Is there a way to migrate parentAReducer first to the reducer protocol style, then update childCReducer and childDReducer?

let parentAReducer = Reducer<ParentState, ParentAction, ParentEnvironment>.combine(
  AnyReducer { _ in
    childBReducer()
  }
  .pullback(
    state: \.childBState, 
    action: /ParentAction.childB, 
    environment: { $0 }
  ),

  childCReducer
    .pullback(
      state: \.childC, 
      action: /ParentAction.childC, 
      environment: {  $0 }
    ),

 childDReducer
    .pullback(
      state: \.childD, 
      action: /ParentAction.childD, 
      environment: {  
        childDEnvironment(date: $0.date)
      }
    ),

  Reducer { state, action, environment in 
    // ...
  }
)

In this case, is that possible to migrate ParentA without migrating childC and childD?