private void AssertFormatTargetKind(SyntaxKind kind, string source)
        {
            var tuple  = GetTreeAndOffset(source);
            var target = Formatting.FindFormatTarget(tuple.Item1, tuple.Item2);

            if (target == null)
            {
                Assert.Null(kind);
            }
            else
            {
                Assert.Equal(kind, target.Kind());
            }
        }