code: def wrap(self, LayoutClass, *args, **kwargs):
          
          def wrap_object(layout_object, j):
              layout_object.fields[j] = self.wrapped_object(
                  LayoutClass, layout_object.fields[j], *args, **kwargs
              )
  
          self.pre_map(wrap_object)
docs: Wraps every layout object pointed in `self.slice` under a `LayoutClass` instance with
          `args` and `kwargs` passed.