mutation UpdateEventInstance($input: UpdateEventInstanceInput!) {
  updateEventInstance(input: $input) {
    clientMutationId
    errors
    eventInstance {
      attendees {
        ambassadorLevel
        ambassadorLevelId
        avatarUrl
        badges {
          __typename
        }
        conversations {
          __typename
        }
        customFieldResponses {
          __typename
        }
      }
      endsAt
      hasNext
      hasPrevious
      id
      instanceIndex
    }
  }
}

{
  "input": {
    "eventId": "id",
    "instanceIndex": "string"
  }
}

{
  "data": {
    "updateEventInstance": {
      "clientMutationId": "string",
      "errors": [
        "string"
      ],
      "eventInstance": {
        "attendees": [
          {
            "ambassadorLevel": "string",
            "ambassadorLevelId": 1,
            "avatarUrl": "string",
            "badges": [
              {
                "__typename": "Badge"
              }
            ],
            "conversations": {
              "__typename": "PublicConversationConnection"
            },
            "customFieldResponses": {
              "__typename": "MemberCustomFieldResponseConnection"
            }
          }
        ],
        "endsAt": "value",
        "hasNext": true,
        "hasPrevious": true,
        "id": "id",
        "instanceIndex": "string"
      }
    }
  }
}