How to use the @keystonejs/fields.Relationship.resolveBacklinks function in @keystonejs/fields

const { Relationship } = require('@keystonejs/fields');
    // Set up a fresh mutation state if we're the root mutation
    const isRootMutation = !mutationState;
    if (isRootMutation) {
      mutationState = {
        afterChangeStack: [], // post-hook stack
        queues: {}, // backlink queues
        transaction: {}, // transaction
      };
    }

    // Perform the mutation
    const { result, afterHook } = await mutation(mutationState);

    // resolve backlinks
    await Relationship.resolveBacklinks(context, mutationState);

    // Push after-hook onto the stack and resolve all if we're the root.
    const { afterChangeStack } = mutationState;
    afterChangeStack.push(afterHook);
    if (isRootMutation) {
      // TODO: Close transaction

      // Execute post-hook stack
      while (afterChangeStack.length) {
        await afterChangeStack.pop()();
      }
    }

    // Return the result of the mutation
    return result;
  }