Apollo delegateToSchema - how to send subquery of child resolver from parent resolver

Question

I have parent schema in graphql that built with apollo libraries apollo-server and graphql-tools that delegates subqueries to remote graphql schema.

For example the query below delegate the subquery of User.booking to the remote schema and it's working well.

const resolvers = {
User: {
        bookings: (parent, args, context, info) => {
        return info.mergeInfo.delegateToSchema({
               schema: subschema,
               operation: 'query',
               fieldName: 'bookingsByUser',
               args: {
                 userId: parent.id,
               },
               context,
               info,
              });
          },
       },
    };

My question is how I can send the subquery of User.books from another resolver (in my case one of his parents resolver - Library) to the remote schema.

From the docs of apollo the function uses the info object in order to extract the wanted subquery:

info: GraphQLResolveInfo

GraphQL resolve info of the current resolver. Provides access to the subquery that starts at the current resolver.