code: def find_one(self, cls, id):
          
          try:
              db_result = self.get_class_table(cls).lookup(id)
          except ItemNotFound:
              # according to docs, this shouldn't be required, but it IS
              db_result = None
  
          if not db_result:
              return None
  
          obj = cls.from_data(db_result['value'])
          return obj
docs: Required functionality.