    # File lib/fog/rackspace/models/block_storage/snapshot.rb, line 27
            def save(force = false)
              requires :volume_id
              raise IdentifierTaken.new('Resaving may cause a duplicate snapshot to be created') if persisted?
              data = service.create_snapshot(volume_id, {
                :display_name => display_name,
                :display_description => display_description,
                :force => force
              })
              merge_attributes(data.body['snapshot'])
              true
            end