# File lib/rdoc/context.rb, line 153
  def add_alias an_alias
    return an_alias unless @document_self

    method_attr = find_method(an_alias.old_name, an_alias.singleton) ||
                  find_attribute(an_alias.old_name, an_alias.singleton)

    if method_attr then
      method_attr.add_alias an_alias, self
    else
      add_to @external_aliases, an_alias
      unmatched_alias_list =
        @unmatched_alias_lists[an_alias.pretty_old_name] ||= []
      unmatched_alias_list.push an_alias
    end

    an_alias
  end