@@ -0,0 +1,269 @@
+package com.github.davidmoten.rx.internal.operators;%0A%0Aimport org.junit.Test;%0A%0Aimport com.github.davidmoten.junit.Asserts;%0A%0Apublic class PermutationsTest %7B%0A    %0A    @Test%0A    public void isUtilClass() %7B%0A        Asserts.assertIsUtilityClass(Permutations.class);%0A    %7D%0A%0A%7D%0A

add test that Permuations is utility class