def active_terminator_window
      active = xdotool("getactivewindow").chomp
      if not all_terminator_windows.include? active
        active = all_terminator_windows.first
      end
      if not active
        abort("No Terminator windows found")
      end
      return active
    end
def active_terminator_window
      active = xdotool("getactivewindow").chomp
      if not all_terminator_windows.include? active
        active = all_terminator_windows.first
      end
      if not active
        abort("No Terminator windows found")
      end
      return active
    end
Get active terminator window winid.
 Gets the active window and returns it if it is
 a Terminator window. If it is not a terminator window,
 the method gets all terminator windows and returns the
 first one. If no terminator windows exist, aborts.

 @api private