package Ġdesign . behavior al . observer Ċ Ċ fun Ġmain () Ġ{ ĊĠĠĠ Ġval Ġcourse Ġ= ĠCourse (" Java è®¾è®¡ æ¨¡å¼ı ") ĊĠĠĠ Ġval Ġteacher Ġ= ĠTe acher (" Alpha ") ĊĊĠĠĠ Ġcourse . add Observer ( teacher ) ĊĠĠĠ Ġval Ġquestion Ġ= ĠQuestion (" Ge ely ", Ġ" ä¸» åĩ½æķ° å¦Ĥä½ķ ç¼ĸåĨĻ ") ĊĠĠĠ Ġcourse . produce Question ( question ) Ċ }