# File lib/parallel_specs.rb, line 4
  def self.run_tests(test_files, process_number, options)
    exe = executable # expensive, so we cache
    version = (exe =~ /\brspec\b/ ? 2 : 1)
    cmd = "#{rspec_1_color if version == 1}#{exe} #{options[:test_options]} #{rspec_2_color if version == 2}#{spec_opts(version)} #{test_files*' '}"
    execute_command(cmd, process_number, options)
  end