Using nested nodes from mutational payload to update local storage

Question

Say I have a typical todo application. There is a mutation CreateTodothat takes a string and returns CreateTodoPayloadwith a newly created edge. The scheme is as follows:

type Todo implements Node {
  id: String!
  content: String!
  user: User!
}

type User implements Node {
  id: String!
  todos: [Todo]
}

input CreateTodoInput {
  clientMutationId: String!
  content: String!
}

type CreateTodoPayload {
  clientMutationId: String!
  todo: Todo
}

How can I indicate that this mutation will update usernode through todousing FIELDS_CHANGE? fieldIDsrequires me to specify an immediate field in the payload, so I can get it to work, also returning the user, but it looks like the relay is trying to execute.

NODE_DELETE, RANGE_ADD RANGE_DELETE ( ), parentName , , , , .. todo.user.