inorganic chemistry - Reaction between silver(I) hydroxide and an alkali

I've read about this in a booklet, but I can't find its stepwise reactions or its derivation:

$$\ce{AgOH + NaOH -> Ag2O}$$

And how does a base ($\ce{AgOH}$) react with another base ($\ce{NaOH}$)? Could someone please explain?