Google Script - add Gmail Attachment to document and Process in Drive

So basically, My father asked me to create a script to find emails with a "Drive" label and save their contents to his drive. (If your asking why, its so he can email himself a couple of PDF's and have the script automatically put them together in his drive)

And I've gotten the whole thing done except for one thing: Can't figure out how to save the attachments. In the processDocument method I loop through the attachments and try to do:

doc.appendParagraph(the attachment)

Is there any proper way of adding the attachments using the processDocument() method?

Link to Code: http://ift.tt/1DcTYOK

Thanks.