public void Next_Defaults()
        {
            var names = new ConcurrentBag <string>();

            Parallel.For(0, 100, _ => names.Add(RandomFileNames.Next()));

            names.Should().HaveCount(100).And.OnlyHaveUniqueItems();
        }
        public void Next_Suffix()
        {
            var names = new ConcurrentBag <string>();

            Parallel.For(0, 100, _ => names.Add(RandomFileNames.Next(suffix: "SUFFIX")));

            names.Should().HaveCount(100).And.OnlyHaveUniqueItems();

            names.Should().OnlyContain(n => n.EndsWith("SUFFIX", StringComparison.Ordinal));
        }
        public void Next_Separator()
        {
            var names = new ConcurrentBag <string>();

            Parallel.For(0, 100, _ => names.Add(RandomFileNames.Next(separator: '!')));

            names.Should().HaveCount(100).And.OnlyHaveUniqueItems();

            NamesShouldHaveCharAtSameIndexes(names, '!');
        }