def add_description(description)
      return if ! description
      comment = description.strip
      add_comment(comment) if comment && ! comment.empty?
    end
def add_description(description)
      return if ! description
      comment = description.strip
      add_comment(comment) if comment && ! comment.empty?
    end
Add a description to the task.  The description can consist of an option
 argument list (enclosed brackets) and an optional comment.