code: def kids(tup_tree):
      
      k = tup_tree[2]
      if k is None:
          return []
      # pylint: disable=unidiomatic-typecheck
      return [x for x in k if type(x) == tuple]
docs: Return a list with the child elements of tup_tree.
  
      The child elements are represented as tupletree nodes.
  
      Child nodes that are not XML elements (e.g. text nodes) in tup_tree are
      filtered out.