+#' There are two variations, depending whether "similar day" means "same day in the week"
+#' or "most recent day" (regardless of day type). The corresponding argument is named
+#' "same_day": a value of TRUE implies the former interpretation (same day in week).
+#' If the last similar day has missing values, the next one is searched, and so on until
+#' one full serie is found (if no one is found, NA is returned).
+#'
+#' @usage # PersistenceForecaster$new(pjump)
+#'
+#' @docType class