def namespace_splitter(self, value):
        """
        Setter for **self.__namespace_splitter** attribute.

        :param value: Attribute value.
        :type value: unicode
        """

        if value is not None:
            assert type(value) is unicode, "'{0}' attribute: '{1}' type is not 'unicode'!".format(
                "namespace_splitter", value)
            assert len(value) == 1, "'{0}' attribute: '{1}' has multiples characters!".format("namespace_splitter",
                                                                                              value)
            assert not re.search(r"\w", value), "'{0}' attribute: '{1}' is an alphanumeric character!".format(
                "namespace_splitter", value)
        self.__namespace_splitter = value