/// <summary>
/// Saves the workbook with the defined name asynchronous.
/// </summary>
/// <param name="fileName">fileName of the saved workbook</param>
/// <returns>Task object (void)</returns>
/// <exception cref="Exceptions.IOException">May throw an IOException in case of an error. The asynchronous operation may hide the exception.</exception>
/// <exception cref="RangeException">May throw a RangeException if the start or end address of a handled cell range was out of range. The asynchronous operation may hide the exception.</exception>
/// <exception cref="Exceptions.FormatException">May throw a FormatException if a handled date cannot be translated to (Excel internal) OADate. The asynchronous operation may hide the exception.</exception>
/// <exception cref="StyleException">May throw a StyleException if one of the styles of the workbook cannot be referenced or is null. The asynchronous operation may hide the exception.</exception>
public async Task SaveAsAsync(string fileName)
{
string backup = fileName;
filename = fileName;
XlsxWriter l = new XlsxWriter(this);
await l.SaveAsync();
filename = backup;
}
/// <summary>
/// Saves the workbook asynchronous.
/// </summary>
/// <returns>Task object (void)</returns>
/// <exception cref="Exceptions.IOException">May throw an IOException in case of an error. The asynchronous operation may hide the exception.</exception>
/// <exception cref="RangeException">May throw a RangeException if the start or end address of a handled cell range was out of range. The asynchronous operation may hide the exception.</exception>
/// <exception cref="Exceptions.FormatException">May throw a FormatException if a handled date cannot be translated to (Excel internal) OADate. The asynchronous operation may hide the exception.</exception>
/// <exception cref="StyleException">May throw a StyleException if one of the styles of the workbook cannot be referenced or is null. The asynchronous operation may hide the exception.</exception>
public async Task SaveAsync()
{
XlsxWriter l = new XlsxWriter(this);
await l.SaveAsync();
}