def addNodes(self, subscription):
    if (self.requesterID != None):
        msg = (' PhEDEx subscription is already made with id: %s\n\n                      Create a new subscription\n                  ' % self.requesterID)
        raise Exception(msg)
    self.nodes = self.nodes.union(subscription.nodes)
    self.subscriptionIds = self.subscriptionIds.union(subscription.subscriptionIds)
def addNodes(self, subscription):
    if (self.requesterID != None):
        msg = (' PhEDEx subscription is already made with id: %s\n\n                      Create a new subscription\n                  ' % self.requesterID)
        raise Exception(msg)
    self.nodes = self.nodes.union(subscription.nodes)
    self.subscriptionIds = self.subscriptionIds.union(subscription.subscriptionIds)