question: 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 ; }
target:  Check if player hasn't received a book too recently (with "too recently" being defined in configuration file).