def setSpecification(self, value):
        if self._Specification is not None:
            filtered = [x for x in self.Specification.Mediums if x != self]
            self._Specification._Mediums = filtered

        self._Specification = value
        if self._Specification is not None:
            if self not in self._Specification._Mediums:
                self._Specification._Mediums.append(self)