code: def testPrepareSessionSucceedsWithInitFn(self):
      with ops.Graph().as_default():
          v = variable_v1.VariableV1([125], name="v")
          sm = session_manager.SessionManager(
              ready_op=variables.report_uninitialized_variables()
          )
          sess = sm.prepare_session(
              "", init_fn=lambda sess: sess.run(v.initializer)
          )
          self.assertAllClose([125], sess.run(v))
  
imports: import os
  from tensorflow.python.checkpoint import checkpoint_management
  from tensorflow.python.client import session
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import errors
  from tensorflow.python.framework import errors_impl
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import resource_variables_toggle
  from tensorflow.python.ops import variable_v1
  from tensorflow.python.ops import variables
  from tensorflow.python.ops import while_loop
  from tensorflow.python.platform import gfile
  from tensorflow.python.platform import test
  from tensorflow.python.training import saver
  from tensorflow.python.training import server_lib
  from tensorflow.python.training import session_manager
label_desc: Use image node_id 4 for calling the SessionManagerTest obj's underlying member method code with example usage: obj.testPrepareSessionSucceedsWithInitFn() without return types