private boolean timeAuthorisedBook(Player player){
  if (player.hasPermission("achievement.*"))   return true;
  long currentTime=System.currentTimeMillis();
  long lastBookTime=0;
  if (players.containsKey(player))   lastBookTime=players.get(player);
  if (currentTime - lastBookTime < bookTime)   return false;
  players.put(player,currentTime);
  return true;
}

private boolean timeAuthorisedBook ( Player player ) { if ( player . hasPermission ( "achievement.*" ) ) return true ; long currentTime = System . currentTimeMillis ( ) ; long lastBookTime = 0 ; if ( players . containsKey ( player ) ) lastBookTime = players . get ( player ) ; if ( currentTime - lastBookTime < bookTime ) return false ; players . put ( player , currentTime ) ; return true ; }
check if player hasn ' t received a book too recently ( with " too recently " being defined in configuration file ) .
