class_docstr: Common tests for single-part and multi-part bijectors.
code: def testClear(self):
      bijector_2 = _BareBonesBijector(
          self.forward_impl, self.inverse_impl
      )
      cache_2 = cache_util.BijectorCache(
          bijector=bijector_2,
          bijector_class=_BareBonesBijector,
          storage=self.cache.storage,
      )
      class_cache = cache_util.BijectorCache(
          bijector=None,
          bijector_class=_BareBonesBijector,
          storage=self.cache.storage,
      )
  
      x = self.test_arg()
      _ = self.forward(x)
      _ = cache_2.forward(x)
  
      y = self.test_arg()
      _ = self.forward(y)
  
      # Class cache has three entries
      self.assertLen(class_cache.weak_keys(direction="forward"), 3)
  
      # Clear entry associated with bijector_2
      cache_2.clear()
      self.assertLen(class_cache.weak_keys(direction="forward"), 2)
  
      # Clear class cache
      class_cache.clear()
      self.assertLen(class_cache.weak_keys(direction="forward"), 0)
  
imports: from absl.testing import parameterized
  import tensorflow.compat.v2
  from tensorflow_probability.python.internal import cache_util
  from tensorflow_probability.python.internal import test_util
label_desc: Use image node_id 5 for calling the CacheTestCommon obj's underlying member method code with example usage: obj.testClear() without return types