code: def testTrace(self):
      def resolve(input_dict):
          result = Foo(input_dict, foo=1)
          result = Bar(result, bar="x")
          return result
  
      rf = resolver_function.ResolverFunction(resolve)
      output_node = rf.trace(DUMMY_INPUT_NODE)
      self.assertEqual(
          repr(output_node), "Bar(Foo(Dict(x=Input()), foo=1), bar='x')"
      )
  
imports: from typing import Mapping, Set
  import tensorflow
  from tfx.dsl.control_flow import for_each
  from tfx.dsl.control_flow import for_each_internal
  from tfx.dsl.input_resolution import resolver_function
  from tfx.dsl.input_resolution import resolver_op
  import tfx.types
  from tfx.types import resolved_channel
  from tfx.utils import typing_utils
label_desc: Use image node_id 1 for calling the ResolverFunctionTest obj's underlying member method code with example usage: obj.testTrace() and returns: result