Hashable object with self references OR how to create a tuple that refers to itself

[Edward C. Jones]

I am trying to create a collection of hashable objects, where each 
object contains references to
other objects in the collection.  The references may be circular.

To simplify, one can define
     x= list()
     x.append(x)
which satisfies x == [x].
Can I create a similar object for tuples which satisfies x == (x,)?