docs: public List<TargetRelationship> getRelatedLevelRelationships() {
          final ArrayList<TargetRelationship> relationships = new ArrayList<TargetRelationship>();
          for (final TargetRelationship relationship : levelRelationships) {
              if (relationship.getType() == RelationshipType.REFER_TO) {
                  relationships.add(relationship);
              }
          }
          return relationships;
      }