def execute(command_line)
      result = collect_result(command_line, *spawn_process(command_line))
      result.wait
      result
    end
def execute(command_line)
      result = collect_result(command_line, *spawn_process(command_line))
      result.wait
      result
    end
Run the command, wait for termination, and collect the results.
 Returns an instance of CommandRunResult that contains the output
 and exit code of the command.