From your question, I can say that you have a problem of understanding how really Java work as an object-oriented (OO) programming language, which is totally different from other language such as C or VB where calling a method is just simply invoked with the method name.
Also from the question, "package" have nothing to do with invoking a method (or in OO, means sending message from one object to another object), "package" will affect the access control of your class or member.
And from your code, clearly show that you did not put your effort to compile and test it ... can you explain whether is it a class ? abstract class ? or interface ? ... if it is a class, how come the method signature end with (); , which is an abstract method without implementation ?
If you keep on with this attitude, you are not able to pick up Java knowledge, not even the fundamental. I suggest you to have a good reference book with you rather than simply study in a mess, and please clarify yourself the concept of class and object.