public void FirstChar()
        {
#if !DEBUG
        Assert.Multiple(() => {
#endif
            var expected = new Dictionary<string, string> { { "s", "saltsoda" }, { "t", "teatoast" } };
            var actual = _object.FirstChar(new[] { "salt", "tea", "soda", "toast" });
            CollectionAssert.AreEquivalent(expected, actual);

            expected = new Dictionary<string, string> { { "a", "aaaAA" }, { "b", "bb" }, { "c", "cccCC" }, { "d", "d" } };
            actual = _object.FirstChar(new[] { "aa", "bb", "cc", "aAA", "cCC", "d" });
            CollectionAssert.AreEquivalent(expected, actual);

            expected = new Dictionary<string, string>();
            actual = _object.FirstChar(new string[0]);
            CollectionAssert.AreEquivalent(expected, actual);

            expected = new Dictionary<string, string> { { "a", "appleaardvark" }, { "b", "bellsbellsbells" }, { "s", "saltsun" }, { "z", "zen" } };
            actual = _object.FirstChar(new[] { "apple", "bells", "salt", "aardvark", "bells", "sun", "zen", "bells" });
            CollectionAssert.AreEquivalent(expected, actual);
#if !DEBUG
});
#endif
        }