Get a debugging representation of this keyed region.
        :return: A string of debugging output.

def dbg_repr(self):
        """
        Get a debugging representation of this keyed region.
        :return: A string of debugging output.
        """
        keys = self._storage.keys()
        offset_to_vars = { }

        for key in sorted(keys):
            ro = self._storage[key]
            variables = [ obj.obj for obj in ro.stored_objects ]
            offset_to_vars[key] = variables

        s = [ ]
        for offset, variables in offset_to_vars.items():
            s.append("Offset %#x: %s" % (offset, variables))
        return "\n".join(s)