Cluster associated with usecase cluster score cannot be explicitly represented
Cluster associated with usecase cluster score cannot be explicitly represented

- It is not possible to use a cluster ForeignKey to represent the cluster
  associated with a usecase cluster score because the root cluster does not
  correspond to a row in the database. Therefore, it is represented implicitly
  using the cluster_id and cluster hierarchy version.

optemo/optemo,optemo/optemo,optemo/optemo,optemo/optemo