#' @param num_leaves number of leaves in one tree. defaults to 127
#' @param max_depth Limit the max depth for tree model. This is used to deal with overfit when #data is small.
#' Tree still grow by leaf-wise.
#' @param num_threads Number of threads for LightGBM. For the best speed, set this to the number of real CPU cores, not the number of threads (most CPU using hyper-threading to generate 2 threads per CPU core).
#' @param eval evaluation function, can be (list of) character or custom eval function
#' @param verbose verbosity for output, if <= 0, also will disable the print of evalutaion during training
#' @param record Boolean, TRUE will record iteration message to \code{booster$record_evals}
#' @param num_leaves number of leaves in one tree. defaults to 127
#' @param max_depth Limit the max depth for tree model. This is used to deal with overfit when #data is small.
#' Tree still grow by leaf-wise.
#' @param num_threads Number of threads for LightGBM. For the best speed, set this to the number of real CPU cores, not the number of threads (most CPU using hyper-threading to generate 2 threads per CPU core).
#' @param eval evaluation function, can be (a list of) character or custom eval function
#' @param verbose verbosity for output, if <= 0, also will disable the print of evalutaion during training
#' @param record Boolean, TRUE will record iteration message to \code{booster$record_evals}