[go-nuts] interface in implementation package or caller

I searched around a bit but couldn't find any discussion on this.

What is recommended, giving an interface with a package, even if the
package doesn't use it itself, or let the callers define the interface?

My specific case is a thing A that exposes a couple methods and a Close().
Then thing B uses thing A but dynamically opens and closes them.

First instinct was that I could provide an interface Aer in the A package
that doesn't include the Close() and then B define an interface ACloser in
the B package as well as a ACreator which defines a Create() (ACloser,
error).
So that is two new interfaces in B and an interface in A, and in my unit
tests it becomes a bit silly.

So this really boils down to, should we include Close() (and perhaps New())
in interfaces? And should the interfaces be in the calling code or
implementing code?