wandblogger

In logging/wandb_logger.py, which define the wandblogger, line 178 and 190, it uses wandb.viz. However, I run the code example for wandblogger and constantly get error message like "module 'wandb' has no attribute 'viz'". I further check that viz is not a feature in the W&B documentation. Can someone take a look at it? If wandb.viz is correctly use, can someone update the example, so that we can learn how to use it simply? Thanks!