Why is There No Mention of the Holy Spirit in Revelation 21?

Some have asked why, in the new heavens and the new earth, we receive of God and of the Lamb but find there is no mention of the Holy Spirit. Surely the answer is that just as, today, Christ has finished his work, and the outcome of that work of Christ is seen in the Church, so, in that day, the Holy Spirit will have finished his work, and the outcome of that work of the Spirit will be seen in the New Jerusalem. For all that is there is real-the full realization by the Spirit of what he came to do. When you touch the Church today, you touch Christ, but it will be no less true that when you touch the City then, you touch the Spirit of Christ. There the Church will be filled with the Spirit of God in his sevenfold fullness; there, as the City, she will manifest in herself the Spirit's work in completeness, for she will be holy, as her Lord.

What is the sevenfold fullness?