public ValueTask MergeCellsAsync(
    TableCellPosition startPosition,
    TableCellPosition endPosition,
    CancellationToken cancellationToken = default(CancellationToken)
)

<DxRichEdit @ref="richEdit" />

@code {
    DxRichEdit richEdit;
    protected override async Task OnAfterRenderAsync(bool firstRender) {
        if (firstRender)
            try {
                await InitializeDocument();
            }
            catch (TaskCanceledException) { }
        await base.OnAfterRenderAsync(firstRender);
    }

    async Task InitializeDocument() {
    /* Surround the code that contains an asynchronous operation with a try-catch block to handle
    the OperationCanceledException. This exception is thrown when an asynchronous operation is canceled. */
        try {
            var columnCount = 4;
            var rowCount = 5;
            richEdit.DocumentAPI.BeginUpdate();
            Table firstTable = await richEdit.DocumentAPI.Tables.CreateAsync(0, columnCount, rowCount);
            var startPosition = new TableCellPosition(0, 0); // The first cell in the first row
            var endPosition = new TableCellPosition(2, 1); // The second cell in the third row
            await firstTable.MergeCellsAsync(startPosition, endPosition);
        }
        catch (OperationCanceledException e) {
            Console.WriteLine($"{nameof(OperationCanceledException)} thrown with message: {e.Message}");
        }
    }
}