import java.util.*; class IDEA101169 { { List<List<UnaryOperator<String>>> intPermutationOfFunctions = perm(asList( s -> s.substring(0), s -> s.substring(0), s -> s.substring(0))); List<UnaryOperator<String>> p = asList( s -> s.substring(0), s -> s.substring(0), s -> s.substring(0)); } public static <T> List<List<T>> perm(List<T> l) { return null; } @SafeVarargs public static <T> List<T> asList(T... a) { return null; } interface UnaryOperator<T> extends Function<T, T> {} interface Function<T, R> { public R apply(T t); } }