def _validate_logical_id(cls, logical_id):
        """Validates that the provided logical id is an alphanumeric string.

        :param str logical_id: the logical id to validate
        :returns: True if the logical id is valid
        :rtype: bool
        :raises TypeError: if the logical id is invalid
        """
        pattern = re.compile(r'^[A-Za-z0-9]+$')
        if logical_id is not None and pattern.match(logical_id):
            return True
        raise InvalidResourceException(logical_id, "Logical ids must be alphanumeric.")