Clarification regarding domain extraction for categorical variables ("PrivacyLeakage" warning)

[jkapar]

@ #18

As previously stated, the documentation now suggests that setting domain=None would handle domain extraction automtically in a DP way, which would be indeed a great feature.

For numerical variables, I found the approx_bounds function which I suppose to handle this if no domain is specified?
Could you please clarify what happens for categorical columns? Without domain specification, these kind of warnings are printed: PrivacyLeakage: No categorical domain provided for Column - will be imputed. The wording "PrivacyLeakage" sort of suggests that the domain for categorical variables is not extracted in a DP-manner as opposed to the statement in the documentation.

Would you please clarify this?