Opens the encrypted PDF file held in bytes with credentials.
public PdfDocument Open(ReadOnlyMemory<byte> bytes, PdfCredentials credentials)
The file. Not copied: do not change it until the document is disposed.
The credentials, such as a PdfPassword; they override those set on the options.
ISO 32000-2 §7.5 and §7.6. For an unencrypted file the credentials are ignored.