code: def testCall_WithNoOutputType(self):
      @resolver_function.resolver_function
      def resolve(*args, **kwargs):
          del args, kwargs
          return DummyNode(resolver_op.DataType.ARTIFACT_MULTIMAP)
  
      with self.subTest(
          "Infer output type if len(args) = 1 and args[0] is Mapping[str, "
          "BaseChannel]."
      ):
          output = resolve(
              {
                  "x": DummyChannel(X),
                  "y": DummyChannel(Y),
              }
          )
          self.assertTrue(
              typing_utils.is_compatible(
                  output, Mapping[str, tfx.types.BaseChannel]
              )
          )
          self.assertEqual(output["x"].type, X)
          self.assertEqual(output["y"].type, Y)
  
      with self.subTest("Cannot infer other kind of args"):
          with self.assertRaisesRegex(
              RuntimeError, "Unable to infer output type"
          ):
              output = resolve(x=DummyChannel(X), y=DummyChannel(Y))
  
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 5 for calling the ResolverFunctionTest obj's underlying member method code with example usage: obj.testCall_WithNoOutputType() and returns: DummyNode