code: private static Function<EntityTypeNode, Set<EntityTypeNode>> getDependencies() {
      return entityTypeNode -> {
        // get referenced entities excluding entities of mappedBy attributes
        EntityType entityType = entityTypeNode.getEntityType();
        Set<EntityTypeNode> refEntityMetaSet =
            stream(entityType.getOwnAllAttributes())
                .filter(attribute -> isProcessableAttribute(attribute, entityType))
                .map(attr -> new EntityTypeNode(attr.getRefEntity()))
                .collect(toCollection(HashSet::new));
  
        EntityType extendsEntityMeta = entityType.getExtends();
        if (extendsEntityMeta != null) {
          refEntityMetaSet.add(new EntityTypeNode(extendsEntityMeta));
        }
        return refEntityMetaSet;
      };
    }
docs: Returns dependencies of the given entity meta data.
  
  @return dependencies of the entity meta data node