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: fetch_command.rb
    path of file: ./repos/truffleruby/lib/mri/rubygems/commands
    
    the code of the file until where you have to start completion: # frozen_string_literal: true
require_relative "../command"
require_relative "../local_remote_options"
require_relative "../version_option"

class Gem::Commands::FetchCommand < Gem::Command
  includ
    
  def arguments # :nodoc:
    "GEMNAME       name of gem to download"
  end

  def defaults_str # :nodoc:
    "--version '#{Gem::Requirement.default}'"
  end

  def description # :nodoc:
    <<-EOF
The fetch command fetches gem files that can be stored for later use or
unpacked to examine their contents.

See the build command help for an example of unpacking a gem, modifying it,
then repackaging it.
    EOF
  end

  def usage # :nodoc:
    "#{program_name} GEMNAME [GEMNAME ...]"
  end

  def check_version # :nodoc:
    if options[:version] != Gem::Requirement.default &&
       get_all_gem_names.size > 1
      alert_error "Can't use --version with multiple gems. You can specify multiple gems with" \
                  " version requirements using `gem fetch 'my_gem:1.0.0' 'my_other_gem:~>2.0.0'`"
      terminate_interaction 1
    end
  end