According to dev document there are no setter methods in data interfaces.
but in application almost every data interface contain setters also. There is no clarity on data interfaces.
According wikipedia an immutable object is an object whose state cannot be modified after it is created. So what objects comes under the category of immutable?
I hope some one will update devdocs properly.
If any one has some knowledge on above things can you give some examples?
It's really tough to understand all new patterns in magento2. Someone should share their knowledge in devdocs otherwise every one fears to see the code.