# File lib/autotest/rspec2.rb, line 48
  def make_test_cmd(files_to_test)
    files_to_test.empty? ? '' :
      "#{prefix}#{ruby}#{suffix} -S #{RSPEC_EXECUTABLE} --tty #{normalize(files_to_test).keys.flatten.map { |f| "'#{f}'"}.join(' ')}"
  end