code: def _add_missing_schema_attributes(self):
          '''
          Adds any missed schema attributes to the _attributes list
  
          The attributes can be class attributes and they won't be
          included in the _attributes list automatically
          '''
          for attr in [attr for attr in dir(self) if not attr.startswith('__')]:
              attr_val = getattr(self, attr)
              if isinstance(getattr(self, attr), SchemaItem) and \
                 attr not in self._attributes:
  
                  self._attributes.append(attrf _add_missing_schema_attributes(self):
          '''
          Adds any missed schema attributes to the _attributes list
  
          The attributes can be class attributes and they won't be
          included in the _attributes list automatically
          '''
          for attr in [attr for attr in dir(self) if not attr.startswith('__')]:
              attr_val = getattr(self, attr)
              if isinstance(getattr(self, attr), SchemaItem) and \
                 attr not in self._attributes:
  
                  self._attributes.append(attr)
docs: Adds any missed schema attributes to the _attributes list
  
          The attributes can be class attributes and they won't be
          included in the _attributes list automatically