code: def getRole(self, label):
          
  
          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)
docs: 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`