code: def test_placeholder_arg(self):
      type_context = trace_type.InternalTracingContext()
      foo = function_type.FunctionType(
          [
              function_type.Parameter(
                  "x",
                  function_type.Parameter.POSITIONAL_ONLY,
                  False,
                  trace_type.from_value(1, type_context),
              ),
              function_type.Parameter(
                  "y",
                  function_type.Parameter.POSITIONAL_OR_KEYWORD,
                  False,
                  trace_type.from_value(2, type_context),
              ),
              function_type.Parameter(
                  "z",
                  function_type.Parameter.KEYWORD_ONLY,
                  False,
                  trace_type.from_value(3, type_context),
              ),
          ]
      )
      context_graph = func_graph.FuncGraph("test")
      placeholder_context = trace_type.InternalPlaceholderContext(
          context_graph
      )
      self.assertEqual(
          foo.placeholder_arguments(placeholder_context).args, (1, 2)
      )
      self.assertEqual(
          foo.placeholder_arguments(placeholder_context).kwargs,
          {"z": 3},
      )
  
imports: import collections
  import pickle
  import platform
  from absl.testing import parameterized
  from tensorflow.core.function import trace_type
  from tensorflow.core.function.polymorphism import function_type
  from tensorflow.core.function.polymorphism import function_type_pb2
  from tensorflow.core.function.trace_type import serialization
  from tensorflow.python.framework import func_graph
  from tensorflow.python.platform import test
  from tensorflow.python.types import trace
label_desc: Use image node_id 5 for calling the TypeHierarchyTest obj's underlying member method code with example usage: obj.test_placeholder_arg() without return types