Opens the PDF file held by stream, from its current position, with default options; a non-seekable stream is read asynchronously.
public static Task<PdfDocument> OpenAsync(Stream stream)
The stream. It is not disposed; a seekable stream must stay open and unchanged until the document is disposed.
ISO 32000-2 §7.5. The same as OpenAsync(Stream, CancellationToken) on an engine with default options.