code: def test_robust_error_on_list_visit(self):
      class BrokenTransformer(transformer.Base):
          def visit_If(self, node):
              # This is broken because visit expects a single node, not a list, and
              # the body of an if is a list.
              # Importantly, the default error handling in visit also expects a single
              # node.  Therefore, mistakes like this need to trigger a type error
              # before the visit called here installs its error handler.
              # That type error can then be caught by the enclosing call to visit,
              # and correctly blame the If node.
              self.visit(node.body)
              return node
  
      def test_function(x):
          if x > 0:
              return x
  
      tr = BrokenTransformer(self._simple_context())
  
      node, _ = parser.parse_entity(test_function, future_features=())
      with self.assertRaises(ValueError) as cm:
          node = tr.visit(node)
      obtained_message = str(cm.exception)
      expected_message = (
          r'expected "ast.AST", got "\<(type|class) \'list\'\>"'
      )
      self.assertRegex(obtained_message, expected_message)
  
imports: import re
  import gast
  from tensorflow.python.autograph.pyct import anno
  from tensorflow.python.autograph.pyct import origin_info
  from tensorflow.python.autograph.pyct import parser
  from tensorflow.python.autograph.pyct import transformer
  from tensorflow.python.platform import test
label_desc: Use image node_id 7 for calling the TransformerTest obj's underlying member method code with example usage: obj.test_robust_error_on_list_visit() and returns: node, x