class ParallelTests::Test::Runner

def execute_command(cmd, process_number, num_processes, options)
  env = (options[:env] || {}).merge(
    "TEST_ENV_NUMBER" => test_env_number(process_number, options).to_s,
    "PARALLEL_TEST_GROUPS" => num_processes.to_s,
    "PARALLEL_PID_FILE" => ParallelTests.pid_file_path,
  )
  cmd = "nice #{cmd}" if options[:nice]
  cmd = "#{cmd} 2>&1" if options[:combine_stderr]
  puts cmd if report_process_command?(options) && !options[:serialize_stdout]
  execute_command_and_capture_output(env, cmd, options)
end