What is the purpose of the change

(For example: This pull request adds the implementation of Naive Bayes algorithm.)

Brief change log

(for example:)

• Adds Transformer and Estimator implementation of Naive Bayes in Java and Python
• Adds examples and documentations of Naive Bayes

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): (yes / no)
• The public API, i.e., is any changed class annotated with @Public(Evolving): (yes / no)

Documentation

• Does this pull request introduce a new feature? (yes / no)
• If yes, how is the feature documented? (not applicable / docs / JavaDocs / not documented)