code: func (s *State) initialize() {
  	if s.stepMap != nil {
  		return
  	}
  
  	s.stepMap = map[string]*Step{}
  	s.stepLookup = map[*milo.Step]*Step{}
  
  	name := "steps"
  	if s.Execution != nil {
  		name = s.Execution.Name
  	}
  	s.rootStep.initializeStep(s, nil, name, false)
  	s.rootStep.LogNameBase = s.LogNameBase
  	s.SetCurrentStep(nil)
  
  	// Add our Command parameters, if applicable.
  	if exec := s.Execution; exec != nil {
  		s.rootStep.Command = &milo.Step_Command{
  			CommandLine: exec.Command,
  			Cwd:         exec.Dir,
  			Environ:     exec.Env,
  		}
  	}
  
  	var annotatedNow *timestamp.Timestamp
  	if !s.Offline {
  		annotatedNow = s.now()
  	}
  	s.rootStep.Start(annotatedNow)
  }
docs: // initialize sets of the State's initial state. It will execute exactly once,
  // and must be called by any State methods that access internal variables.