code: def fill_default(self):
          
          for prop, entry in self.__class__.properties.items():
              if hasattr(self, prop):
                  continue
              if not hasattr(entry, 'default') or entry.default is NONE_OBJECT:
                  continue
  
              if hasattr(entry.default, '__iter__'):
                  setattr(self, prop, copy(entry.default))
              else:
                  setattr(self, prop, entry.default)
docs: Define the object properties with a default value when the property is not yet defined
  
          :return: None