code: @Override
  	public void put(Object entity) {
  		if (entity == null) {
  			throw new IllegalArgumentException("'entity' must not be [" + entity + "]");
  		}
  		
  		if (operation != null) {
  			throw new IllegalStateException("Log [" + operation + "] -> ["
  					+ Log.Operation.PUT
  					+ "] is not allowed: This operation must be first");
  		}
  		
  		Key id = Keys.create(Translation.toKind(entity.getClass()), Entities.keyValue(entity));
  		Entity e = datastore.get(local, id);
  		
  		if (e != null) {
  			throw new EntityExistsException(id);
  		}
  		
  		this.entity = entity;
  		operation = Log.Operation.PUT;
  	}
docs: Puts the specified entity instance into the Google App Engine Datastore
  newly.
  
  @param entity An entity instance.