code: public Collection<Object> persist(Collection<Object> objColl) {
      if (null == objColl) {
        throw new IllegalArgumentException("object to save cannot be null");
      }
  
      objMapper.saveObjCollection(keyspace, objColl);
      return objColl;
    }
docs: Save the list of entity intances.
  
  @param objColl
  @return