code: function() {
      var finalState = this.finalState, initialState;
  
      while(true) {
        initialState = get(finalState, 'initialState') || 'start';
        finalState = get(finalState, 'states.' + initialState);
  
        if (!finalState) { break; }
  
        this.finalState = finalState;
        this.enterStates.push(finalState);
        this.contexts.push(undefined);
      }
    }
docs: @private
  
  Add any `initialState`s to the list of enter states.