PSPDFkit pdf flattening and saving

gistfile1.m

// pdf delivery
-(void)deliverPDFAttachment {
    NSLog(@"this is attachment path %@", attachmentPath);
    NSURL *documentURL = [NSURL fileURLWithPath:attachmentPath];
    PSPDFDocument *document = [PSPDFDocument PDFDocumentWithURL:documentURL];
    
    document.editableAnnotationTypes = [NSSet setWithObjects:
                                        PSPDFAnnotationTypeStringLink, // not added by default.
                                        PSPDFAnnotationTypeStringHighlight,
                                        PSPDFAnnotationTypeStringUnderline,
                                        PSPDFAnnotationTypeStringStrikeout,
                                        PSPDFAnnotationTypeStringNote,
                                        PSPDFAnnotationTypeStringFreeText,
                                        PSPDFAnnotationTypeStringInk,
                                        PSPDFAnnotationTypeStringSquare,
                                        PSPDFAnnotationTypeStringCircle,
                                        nil];
    document.delegate = delegate;
    
    // Open view controller. Embed into an UINavigationController to enable the toolbar.
    PSPDFViewController *pdfController =
    [[PSCExampleAnnotationViewController alloc] initWithDocument:document];
    
    [[delegate navigationController] pushViewController:pdfController animated:YES];
}

// PSPDFDocumentDelegate
- (void)pdfDocument:(PSPDFDocument *)document didSaveAnnotations:(NSArray *)annotations {
    NSLog(@"\n\nSaving of %@ successful: %@", document, annotations);
    NSLog(@"will save flattened annotation to %@",[NSString stringWithFormat:@"%@_annotated",_attachmentPath]);
    
    [[PSPDFProcessor defaultProcessor] generatePDFFromDocument:document 
      pageRange:[NSIndexSet indexSetWithIndexesInRange:NSMakeRange(0, document.pageCount)] 
  outputFileURL:[NSURL URLWithString:[NSString stringWithFormat:@"%@_annotated",_attachmentPath]] 
        options:@{kPSPDFProcessorAnnotationTypes : @(PSPDFAnnotationTypeAll)} 
          error:NULL];    
}