How to use the @aws-cdk/aws-cognito.SignInType.EMAIL function in @aws-cdk/aws-cognito

});

    // ========================================================================
    // Resource: Amazon Cognito User Pool
    // ========================================================================

    // Purpose: creates a user directory and allows federation from external IdPs

    // See also:
    // - https://aws.amazon.com/cognito/
    // - https://docs.aws.amazon.com/cdk/api/latest/docs/@aws-cdk_aws-cognito.CfnIdentityPool.html


    // high level construct
    const userPool: UserPool = new cognito.UserPool(this, id + "Pool", {
      signInType: SignInType.EMAIL,
      autoVerifiedAttributes: [UserPoolAttribute.EMAIL],
      lambdaTriggers: {preTokenGeneration: preTokenGeneration}
    });

    // any properties that are not part of the high level construct can be added using this method
    const userPoolCfn = userPool.node.defaultChild as CfnUserPool;
    userPoolCfn.schema = [{
      name: groupsAttributeName,
      attributeDataType: "String",
      mutable: true,
      required: false,
      stringAttributeConstraints: {
        maxLength: "2000"
      }
    }];