class Gem::Commands::SourcesCommand

def add_source source_uri # :nodoc:
  check_rubygems_https source_uri
  source = Gem::Source.new source_uri
  begin
    if Gem.sources.include? source_uri then
      say "source #{source_uri} already present in the cache"
    else
      source.load_specs :released
      Gem.sources << source
      Gem.configuration.write
      say "#{source_uri} added to sources"
    end
  rescue URI::Error, ArgumentError
    say "#{source_uri} is not a URI"
    terminate_interaction 1
  rescue Gem::RemoteFetcher::FetchError => e
    say "Error fetching #{source_uri}:\n\t#{e.message}"
    terminate_interaction 1
  end
end