Groovy多方法

public class Func {	public static void main(String[] args) {		Sub sub = new Sub();		Main m = sub;		MainFunction func = new SubFunction();		m.print(func);	}		public static class Main {		void print(MainFunction fun) {			System.out.println("Main");		}			}		public static class MainFunction {	}		public static class Sub extends Main {		@Override		void print(MainFunction fun) {			System.out.println("Sub mainFunction");		}				void print(SubFunction fun) {			System.out.println("Sub subFunction");		}			}		public static class SubFunction extends MainFunction {	}}Java返回Sub mainFunctionGroovy返回Sub subFunction