code: def key_from_dict(**kwargs):
      
      out = []
      stack = [kwargs]
      while stack:
          obj = stack.pop()
          if isinstance(obj, dict):
              stack.extend(sorted(obj.items()))
          elif isinstance(obj, (list, tuple)):
              stack.extend(obj)
          else:
              out.append(str(obj))
      return ''.join(out)
docs: Return a unique string representation of a dict as quickly as possible.
      Used to generated deduplication keys from a request.