code: async def verify_task_types(chain):
      
      valid_task_types = get_valid_task_types()
      task_count = {}
      for obj in chain.get_all_links_in_chain():
          task_type = obj.task_type
          log.info("Verifying {} {} as a {} task...".format(obj.name, obj.task_id, task_type))
          task_count.setdefault(task_type, 0)
          task_count[task_type] += 1
          # Run tests synchronously for now.  We can parallelize if efficiency
          # is more important than a single simple logfile.
          await valid_task_types[task_type](chain, obj)
      return task_count
docs: Verify the task type (e.g. decision, build) of each link in the chain.
  
      Args:
          chain (ChainOfTrust): the chain we're operating on
  
      Returns:
          dict: mapping task type to the number of links.