    # File lib/fog/ibm/models/storage/volume.rb, line 83
            def save
              raise Fog::Errors::Error.new('Resaving an existing object may create a duplicate') if persisted?
              requires :name, :offering_id, :format, :location_id, :size
              data = service.create_volume(name, offering_id, format, location_id, size)
              merge_attributes(data.body)
              true
            end