code: def _init_metadata(self):
          
          SimpleDifficultyItemFormRecord._init_metadata(self)
          SourceItemFormRecord._init_metadata(self)
          PDFPreviewFormRecord._init_metadata(self)
          PublishedFormRecord._init_metadata(self)
          ProvenanceFormRecord._init_metadata(self)
          super(MecQBankBaseMixin, self)._init_metadata()
docs: stub