Finding all Images in a FlowDocument

Question

Since I am pretty new to WPF FlowDocuments I would like to ask if the code below is correct. It is supposed to return all Images contained in a FlowDocument as List:

Answer 1

Little change in Code to add coverage for List

    public static IEnumerable FindImages(FlowDocument document)
    {
        return document.Blocks.SelectMany(block => FindImages(block));
    }

    public static IEnumerable FindImages(Block block)
    {
        if (block is Table)
        {
            return ((Table)block).RowGroups
                .SelectMany(x => x.Rows)
                .SelectMany(x => x.Cells)
                .SelectMany(x => x.Blocks)
                .SelectMany(innerBlock => FindImages(innerBlock));
        }
        if (block is Paragraph)
        {
            return ((Paragraph)block).Inlines
                .OfType()
                .Where(x => x.Child is Image)
                .Select(x => x.Child as Image);
        }
        if (block is BlockUIContainer)
        {
            Image i = ((BlockUIContainer)block).Child as Image;
            return i == null
                        ? new List()
                        : new List(new[] { i });
        }
        if (block is List)
        {
            return ((List)block).ListItems.SelectMany(listItem => listItem
                                                                  .Blocks
                                                                  .SelectMany(innerBlock => FindImages(innerBlock)));
        }
        throw new InvalidOperationException("Unknown block type: " + block.GetType());
    }