    # File lib/fog/rackspace/models/block_storage/volume.rb, line 43
            def save
              requires :size
              raise IdentifierTaken.new('Resaving may cause a duplicate volume to be created') if persisted?
              data = service.create_volume(size, {
                :display_name => display_name,
                :display_description => display_description,
                :volume_type => volume_type,
                :availability_zone => availability_zone
              })
              merge_attributes(data.body['volume'])
              true
            end