code: private Referenceable registerInstance(Referenceable referenceable) throws Exception {
          String typeName = referenceable.getTypeName();
          LOG.debug("creating instance of type {}", typeName);
  
          String entityJSON = InstanceSerialization.toJson(referenceable, true);
          LOG.debug("Submitting new entity {} = {}", referenceable.getTypeName(), entityJSON);
          List<String> guids = getAtlasClient().createEntity(entityJSON);
          LOG.debug("created instance for type {}, guid: {}", typeName, guids);
  
          return new Referenceable(guids.get(guids.size() - 1), referenceable.getTypeName(), null);
      }
docs: Registers an entity in atlas
  @param referenceable
  @return
  @throws Exception