code: public EntityResult updateEntity(final String entityType, final String uniqueAttributeName,
                                       final String uniqueAttributeValue,
                                       Referenceable entity) throws AtlasServiceException {
          final API api = API.UPDATE_ENTITY_PARTIAL;
          String entityJson = InstanceSerialization.toJson(entity, true);
          LOG.debug("Updating entity type: {}, attributeName: {}, attributeValue: {}, entity: {}", entityType,
                  uniqueAttributeName, uniqueAttributeValue, entityJson);
          JSONObject response = callAPIWithRetries(api, entityJson, new ResourceCreator() {
              @Override
              public WebResource createResource() {
                  WebResource resource = getResource(api, QUALIFIED_NAME);
                  resource = resource.queryParam(TYPE, entityType);
                  resource = resource.queryParam(ATTRIBUTE_NAME, uniqueAttributeName);
                  resource = resource.queryParam(ATTRIBUTE_VALUE, uniqueAttributeValue);
                  return resource;
              }
          });
          EntityResult result = extractEntityResult(response);
          LOG.debug("Update entity returned result: {}", result);
          return result;
      }
docs: Supports Partial updates
  Updates properties set in the definition for the entity corresponding to guid
  @param entityType Type of the entity being updated
  @param uniqueAttributeName Attribute Name that uniquely identifies the entity
  @param uniqueAttributeValue Attribute Value that uniquely identifies the entity
  @param entity entity definition