code: func (s *stack) PopBool() (bool, error) {
  	so, err := s.PopByteArray()
  	if err != nil {
  		return false, err
  	}
  
  	return asBool(so), nil
  }
docs: // PopBool pops the value off the top of the stack, converts it into a bool, and
  // returns it.
  //
  // Stack transformation: [... x1 x2 x3] -> [... x1 x2]