Is AdamW identical to Adam in Keras?

python - AdamW and Adam with weight decay - Stack Overflow

According to the above StackOverflow discussion, Adam and AdamW are identical in Keras (except for the default value of weight_decay). I have checked the update_step method of these classes and they are indeed identical, whereas the pseudocode provided in the above link shows that they should be different.

Is this a Keras bug? And can anyone tell me whether the Keras implementation of these classes is for Adam or AdamW?