def fetch
      instance = id ? find(id, computed_scope) : build(build_params, computed_scope)
      decorate(instance)
    end
def fetch
      instance = id ? find(id, computed_scope) : build(build_params, computed_scope)
      decorate(instance)
    end
Public: Fetches a scope.

 Finds an object. If it isn't found, the object gets instantiated.

 Returns the decorated object.