code: def testMarkUsed(self):
      @tf_should_use.should_use_result(warn_in_eager=True)
      def return_const(value):
          return constant_op.constant(value, name="blah3")
  
      with self.cached_session():
          return_const(0.0).mark_used()
  
imports: import contextlib
  import gc
  import sys
  from tensorflow.python.eager import context
  from tensorflow.python.eager import def_function
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import test_util
  from tensorflow.python.platform import test
  from tensorflow.python.platform import tf_logging
  from tensorflow.python.util import tf_should_use
label_desc: Use image node_id 8 for calling the TfShouldUseTest obj's underlying member method code with example usage: obj.testMarkUsed() and returns: constant_op