# File lib/rubygems/commands/yank_command.rb, line 31
  def execute
    sign_in
    version   = get_version_from_requirements(options[:version])
    platform  = get_platform_from_requirements(options)
    
    if !version.nil?
      if options[:undo]
        unyank_gem(version, platform)
      else
        yank_gem(version, platform)
      end
    else
      say "A version argument is required: #{usage}"
      terminate_interaction
    end
  end