Major Description
It has been discovered that there is a fair bit of consistency in the documentation of summary functions, eg.
#' @return \code{summary} returns a summary object of the fitted model, a list of components #' including formula, number of features, list of features, feature importances, number of #' trees, and tree weights setMethod("summary", signature(object = "GBTRegressionModel")
For instance, what should be listed for the return value? Should it be a name or a phrase, or should it be a list of items; and should there be a longer description on what they mean, or reference link to Scala doc.
We will need to review this for all model summary implementations in mllib.R
