public void FlattenAnnotations(
    params string[] names
)

Public Sub FlattenAnnotations(
    ParamArray names As String()
)

using (PdfDocumentProcessor processor = new PdfDocumentProcessor())
{
  // Load a document
  processor.LoadDocument("..\\..\\Document.pdf");
  PdfDocumentFacade documentFacade = processor.DocumentFacade;

  var annotations = processor.DocumentFacade.Pages[0].Annotations;
  string[] names = { annotations[0].Name, annotations[1].Name };

  // Flatten annotations with specified names
  documentFacade.FlattenAnnotations(names);

  // Save the result
  processor.SaveDocument("..\\..\\Result.pdf");
}
System.Diagnostics.Process.Start("..\\..\\Result.pdf");

Using processor As New PdfDocumentProcessor()
  ' Load a document
  processor.LoadDocument("..\..\Document.pdf")
  Dim documentFacade As PdfDocumentFacade = processor.DocumentFacade

  Dim annotations = processor.DocumentFacade.Pages(0).Annotations
  Dim names() As String = { annotations(0).Name, annotations(1).Name }

  ' Flatten annotations with specified names
  documentFacade.FlattenAnnotations(names)

  ' Save the result
  processor.SaveDocument("..\..\Result.pdf")
End Using
System.Diagnostics.Process.Start("..\..\Result.pdf")