docs: def delete_all(self, model_class):
          '''Drop all records from the table model_class.__name__.lower()
          '''
          assert hasattr(model_class, '_fields'), 'Not a valid model class'
  
          table = model_class.__name__.lower()
          with Session() as conn:
              SQL = f'DELETE FROM {table}'
              conn.cursor().execute(SQL)
              conn.commit()