code: @Override
  	public <T extends Resource> T attach(String attachmentId, ResourceId resourceId, Class<? extends T> clazz) {
  		checkNotNull(attachmentId,"Attachment identifier cannot be null");
  		checkNotNull(resourceId,"Attached resource identifier cannot be null");
  		checkNotNull(clazz,"Attached resource class cannot be null");
  		this.attachmentCollection.checkNotAttached(attachmentId,resourceId);
  		ResourceTemplate attachmentTemplate=super.getTemplate(resourceId);
  		checkState(Resources.areCompatible(clazz,attachmentTemplate),"Attachment '%s' is not of type '%s' (%s)",attachmentId,clazz.getCanonicalName(),attachmentTemplate.getClass().getCanonicalName());
  		JPAResource newResource=createChild(resourceId,attachmentTemplate);
  		JPAAttachment newAttachment=this.attachmentCollection.attachmentById(attachmentId);
  		newAttachment.bind(resourceId);
  		return clazz.cast(newResource);
  	}
docs: {@inheritDoc}