code: def payload(self) -> str:
      blocks = [self.header]
  
      if self.n_failures > 0:
          blocks.append(self.failures)
  
      if self.n_failures > 0:
          blocks.extend([self.category_failures])
  
      if self.n_failures == 0:
          blocks.append(self.no_failures)
  
      return json.dumps(blocks)
  
imports: import collections
  import json
  import math
  import os
  import re
  import time
  from fnmatch import fnmatch
  from typing import Dict
  import requests
  from slack_sdk import WebClient
label_desc: Use image node_id 7 for calling the Message obj's underlying member method code with example usage: obj.payload() and returns: json