public Interface Predicate {
	public boolean isTruthy(Object o);
}

public abstract class Filter {
	public abstract makePredicate(int k);
}

public class TimeFilter extends Filter {
	public Predicate makePredicate(int k) {
		return new Predicate() {
			public boolean isTruthy(Object o) {
				return o.someBoolean;
			}
		}
	}
}