def set_cts_property(self, prop, value, lang=None):
        """ Set given property in CTS Namespace

        .. example::
            collection.set_cts_property("groupname", "MyCapytain", "eng")

        :param prop: Property to set (Without namespace)
        :param value: Value to set for given property
        :param lang: Language to set for given value
        """
        if not isinstance(value, Literal):
            value = Literal(value, lang=lang)
        prop = RDF_NAMESPACES.CTS.term(prop)

        if prop == self.DC_TITLE_KEY:
            self.set_label(value, lang)

        self.metadata.add(prop, value)