Using private is this way with class methods doesn't work and is effectively a comment, how about I add a fix to actually make them class methods using the `private_class_method` keyword.

It looks like everything but `self.by_steps` should be private as that is the only method that gets called outside this class. What do you think?

eg.

    def self.build_features_with_steps
      ...
    end
    private_class_method :build_features_with_steps