code: def find(self, id, columns=None):
          
          if columns is None:
              columns = ["*"]
  
          if isinstance(id, list):
              return self.find_many(id, columns)
  
          self._query.where(self._model.get_qualified_key_name(), "=", id)
  
          return self.first(columns)
docs: Find a model by its primary key
  
          :param id: The primary key value
          :type id: mixed
  
          :param columns: The columns to retrieve
          :type columns: list
  
          :return: The found model
          :rtype: orator.Model