code: def testDeleteRemovesConcreteFunctions(self):
      cache = function_cache.FunctionCache()
      f_type_1 = make_type(1)
      cache.add(MockFunction(f_type_1, "test_1"))
      self.assertEqual(cache.lookup(f_type_1).test_string, "test_1")
      cache.delete(f_type_1)
      self.assertIsNone(cache.lookup(f_type_1))
  
      f_type_2 = make_single_param_type(MockSubtypeOf2(2))
      cache.add(MockFunction(f_type_2, "test_2"))
      self.assertEqual(cache.lookup(f_type_2).test_string, "test_2")
  
      f_type_3 = make_single_param_type(MockSubtypeOf2(3))
      self.assertEqual(cache.lookup(f_type_3).test_string, "test_2")
  
      cache.delete(f_type_2)
      self.assertIsNone(cache.lookup(f_type_2))
      self.assertIsNone(cache.lookup(f_type_3))
  
imports: import dataclasses
  import itertools
  import timeit
  from typing import Any, Optional
  from tensorflow.core.function import trace_type
  from tensorflow.core.function.polymorphism import function_cache
  from tensorflow.core.function.polymorphism import function_type
  from tensorflow.python.ops import array_ops
  from tensorflow.python.platform import test
  from tensorflow.python.types import trace
label_desc: Use image node_id 3 for calling the FunctionCacheTest obj's underlying member method code with example usage: obj.testDeleteRemovesConcreteFunctions() without return types