public DocumentVersion(AttachmentDetail attachment) {
   this.creationDate = attachment.getCreationDate();
   this.physicalName = attachment.getPhysicalName();
   this.logicalName = attachment.getLogicalName();
   this.mimeType = attachment.getType();
   this.size = attachment.getSize();
   this.instanceId = attachment.getPK().getInstanceId();
 }