# File lib/automateit/package_manager/gem.rb, line 16
  def installed?(*packages)
    return _installed_helper?(*packages) do |list, opts|
      cmd = "gem list --local 2>&1"

      log.debug(PEXEC+cmd)
      data = `#{cmd}`

      # Gem lists packages out of order, which screws up the
      # install/uninstall sequence, so we need to put them back in the
      # order that the user specified.
      present = data.scan(/^([^\s\(]+)\s+\([^\)]+\)\s*$/).flatten
      available = []
      for package in list
        available << package if present.include?(package)
      end
      available
    end
  end