code: def with_start_after(self, after_namespace):
      
      namespace_start = _ord_to_namespace(_namespace_to_ord(after_namespace) + 1)
      return NamespaceRange(namespace_start, self.namespace_end, _app=self.app)
docs: Returns a copy of this NamespaceName with a new namespace_start.
  
      Args:
        after_namespace: A namespace string.
  
      Returns:
        A NamespaceRange object whose namespace_start is the lexographically next
        namespace after the given namespace string.
  
      Raises:
        ValueError: if the NamespaceRange includes only a single namespace.