docs: def set_username(self, username = None):
          """This method is used to set the username.
  
          username must be a string.
  
          """
          
          if username is None or type(username) is not str:
              raise KPError("Need a new image number")
          else:
              self.username = username
              self.last_mod = datetime.now().replace(microsecond=0)
              return True