# File lib/automateit/package_manager.rb, line 82
  def _installed_helper?(*packages, &block) # :yields: filtered_packages, opts
    _raise_unless_available

    packages, opts = args_and_opts(*packages)
    packages = _list_normalizer(packages)
    packages = packages.keys if Hash === packages

    available = block.call(packages, opts)
    truth = (packages - available).empty?
    result = opts[:details] ? [truth, available] : truth
    log.debug(PNOTE+"installed?(#{packages.inspect}) => #{truth}: #{available.inspect}")
    return result
  end