You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: extend-command.rb
    path of file: ./repos/ruby-packer/ruby/lib/irb
    
    the code of the file until where you have to start completion: # frozen_string_literal: false
#
#   irb/extend-command.rb - irb extend command

    
    def self.def_extend_command(cmd_name, cmd_class, load_file = nil, *aliases)
      case cmd_class
      when Symbol
        cmd_class = cmd_class.id2name
      when String
      when Class
        cmd_class = cmd_class.name
      end