尝试实现graphene-pynamodb 2.1.0库时出现错误，因为它引发错误并且不允许我咨询dynamodb

Question

我想要的是能够通过Grapheno与GraphQL进行结构化咨询。

执行守则。

from uuid import uuid4
from pynamodb.attributes import UnicodeAttribute
from pynamodb.models import Model
import graphene
from graphene_pynamodb import PynamoObjectType


class User(Model):
  class Meta:
    table_name = 'tabla'
    region = 'us-east-1'
    host = 'https://dynamodb.us-east-1.amazonaws.com'
  id = UnicodeAttribute(hash_key=True, null=False)
  discipline = UnicodeAttribute(null=False)

class UserNode(PynamoObjectType):
  class Meta:
    model = User
    interfaces = (graphene.Node,)

class Query(graphene.ObjectType):
  users = graphene.List(UserNode)
  def resolve_users(self, args, context, info):
    return list(User.scan())

schema = graphene.Schema(query=Query)

def patrongrafico(event, context):
  # fetch all todos from the database
  try:
    print("hola")
    query = '''
        users {
          discipline
        }
      '''
    results = schema.execute(query)
    print(results)
  except Exception as ex:
    print(ex)
  return {'statusCode': 200,
    'body': json.dumps({'items': [dict(result) for result in results]})}

但是在安装库和实现官方页面（ https://pypi.org/project/graphene-pynamodb/ ）的代码时，它会向我抛出以下错误：

Traceback (most recent call last):
  File "prueba.py", line 5, in <module>
    from graphene_pynamodb import PynamoObjectType
  File "/home/maxxis/Escritorio/max/severless/AWS-P4/env/lib/python3.6/site-packages/graphene_pynamodb/__init__.py", line 4, in <module>
    from .types import (
  File "/home/maxxis/Escritorio/max/severless/AWS-P4/env/lib/python3.6/site-packages/graphene_pynamodb/types.py", line 11, in <module>
    from .converter import convert_pynamo_attribute
  File "/home/maxxis/Escritorio/max/severless/AWS-P4/env/lib/python3.6/site-packages/graphene_pynamodb/converter.py", line 62, in <module>
    @convert_pynamo_attribute.register(attributes.LegacyBooleanAttribute)
AttributeError: module 'pynamodb.attributes' has no attribute 'LegacyBooleanAttribute'

感谢您的帮助。