public void OneItemIsOk()
 {
     var strings = new[] { "s1" };
     strings.Merge(",").ShouldBe("s1");
 }
 public void EmptySeparatorIsOk()
 {
     var strings = new[] { "s1", "s2" };
     var merge = strings.Merge("");
     merge.ShouldBe("s1s2");
 }
 public void NullSeparatorIsOk()
 {
     var strings = new[] { "s1", "s2" };
     strings.Merge(null).ShouldBe("s1s2");
 }