code: func makeString(s string) *Automaton {
  	a := newEmptyAutomaton()
  	lastState := a.createState()
  	for _, r := range s {
  		state := a.createState()
  		a.addTransitionRange(lastState, state, int(r), int(r))
  		lastState = state
  	}
  
  	a.setAccept(lastState, true)
  	a.finishState()
  
  	assert(a.deterministic)
  	assert(!hasDeadStates(a))
  
  	return a
  }
docs: // L237
  // Returns a new (deterministic) automaton that accepts the single given string