+ " be dropped, or missing values used.";
+ " be dropped, or missing values used. Skips the class attribute if it is set.";
  public String globalInfo() {    return "An instance filter that assumes instances form time-series data and "      + "replaces attribute values in the current instance with the equivalent "      + "attribute attribute values of some previous (or future) instance. For "      + "instances where the desired value is unknown either the instance may "      + " be dropped, or missing values used.";  }