code: func (v *Context) Exit() {
  	if len(v.element) != 0 {
  		v.element = v.element[:len(v.element)-1]
  	}
  }
docs: // Exit pops the current element we are visiting from the stack.
  //
  // This is the reverse of Enter. Each Enter must have corresponding Exit. Use
  // functions and defers to ensure this, if it's otherwise hard to track.