def duplicate(self):
# duplicate the attachment
attachment = Attachment()
attachment._key_name = self.tgt_key
attachment.put()
#duplicate the file parts
for blobpart in self.blobparts:
new_blobpart = BlobPart(parent=attachment)
new_blobpart.blobEntity = attachment
new_blobpart.content = blobpart.content
new_blobpart.partNo = blobpart.partNo
new_blobpart.put()
