code: public EntityResult updateEntity(String guid, Referenceable entity) throws AtlasServiceException {
          String entityJson = InstanceSerialization.toJson(entity, true);
          LOG.debug("Updating entity id {} with {}", guid, entityJson);
          JSONObject response = callAPIWithBodyAndParams(API.UPDATE_ENTITY_PARTIAL, entityJson, guid);
          return extractEntityResult(response);
      }
docs: Supports Partial updates
  Updates properties set in the definition for the entity corresponding to guid
  @param guid      guid
  @param entity entity definition