docs: def get_meta_clusters(self, clusters):
          """
          Returns a dictionary keyed off of meta cluster names, where the values
          are lists of clusters associated with the meta cluster name.
  
          If a meta cluster name doesn't have a port defined in the
          `meta_cluster_ports` attribute an error is given and the meta cluster
          is removed from the mapping.
          """
          meta_clusters = collections.defaultdict(list)
  
          for cluster in clusters:
              if not cluster.meta_cluster:
                  continue
              meta_clusters[cluster.meta_cluster].append(cluster)
  
          unconfigured_meta_clusters = [
              name for name in meta_clusters.keys()
              if name not in self.meta_clusters
          ]
  
          for name in unconfigured_meta_clusters:
              logger.error("Meta cluster %s not configured!")
              del meta_clusters[name]
  
          return meta_clusters