code: public static Specification<JpaRollout> isDeletedWithDistributionSet(final Boolean isDeleted) {
          return (root, query, cb) -> {
  
              final Predicate predicate = cb.equal(root.<Boolean> get(JpaRollout_.deleted), isDeleted);
              root.fetch(JpaRollout_.distributionSet);
              return predicate;
          };
  
      }
docs: {@link Specification} for retrieving {@link Rollout}s by its DELETED
  attribute. Includes fetch for stuff that is required for {@link Rollout}
  queries.
  
  @param isDeleted
  TRUE/FALSE are compared to the attribute DELETED. If NULL the
  attribute is ignored
  @return the {@link Rollout} {@link Specification}