code: func (n *builderNode) reset() {
  	n.final = false
  	n.finalOutput = 0
  	for i := range n.trans {
  		n.trans[i] = emptyTransition
  	}
  	n.trans = n.trans[:0]
  	n.next = nil
  }
docs: // reset resets the receiver builderNode to a re-usable state.