code: func (c *PodConfig) SeenAllSources(seenSources sets.String) bool {
  	if c.pods == nil {
  		return false
  	}
  	klog.V(5).Infof("Looking for %v, have seen %v", c.sources.List(), seenSources)
  	return seenSources.HasAll(c.sources.List()...) && c.pods.seenSources(c.sources.List()...)
  }
docs: // SeenAllSources returns true if seenSources contains all sources in the
  // config, and also this config has received a SET message from each source.