Get the :class:`rtcclient.models.Role` object by the label name

        :param label: the label name of the role
        :return: the :class:`rtcclient.models.Role` object
        :rtype: :class:`rtcclient.models.Role`

def getRole(self, label):
        """Get the :class:`rtcclient.models.Role` object by the label name

        :param label: the label name of the role
        :return: the :class:`rtcclient.models.Role` object
        :rtype: :class:`rtcclient.models.Role`
        """

        if not isinstance(label, six.string_types) or not label:
            excp_msg = "Please specify a valid role label"
            self.log.error(excp_msg)
            raise exception.BadValue(excp_msg)

        roles = self.getRoles()
        if roles is not None:
            for role in roles:
                if role.label == label:
                    self.log.info("Get <Role %s> in <ProjectArea %s>",
                                  role, self)
                    return role

        excp_msg = "No role's label is %s in <ProjectArea %s>" % (label,
                                                                  self)
        self.log.error(excp_msg)
        raise exception.NotFound(excp_msg)