docstr: Update cluster when other function are registered and removed.
docstr_tok: ["Update","cluster","when","other","function","are","registered","and","removed","."]
code: def testFunctionRegisteredAndRemoved(self):
      """Update cluster when other function are registered and removed."""
      with ops.device(self.device_local):
          x1 = array_ops.ones([2, 2])
  
      num_calls = 30
      self._coord = coordinator.Coordinator()
  
      def update_server_def_fn():
          with self._coord.stop_on_exception():
              for i in range(num_calls):
                  context.update_server_def(
                      server_def=(
                          self.server_def_s1_s2
                          if i % 2 == 0
                          else self.server_def_s1_s3
                      )
                  )
  
      t = threading.Thread(target=update_server_def_fn)
      t.start()
  
      for _ in range(num_calls):
  
          @def_function.function
          def worker_fn(i):
              return math_ops.matmul(i, i)
  
          concrete_fn = worker_fn.get_concrete_function(x1)
          del concrete_fn
          del worker_fn
  
      # No exception should be thrown from the thread
      self._coord.join([t])
  
imports: import os
  import threading
  from absl.testing import parameterized
  import numpy
  from tensorflow.core.distributed_runtime.preemption import gen_check_preemption_op
  from tensorflow.core.protobuf import cluster_pb2
  from tensorflow.core.protobuf import tensorflow_server_pb2
  from tensorflow.python import pywrap_tfe
  from tensorflow.python.eager import context
  from tensorflow.python.eager import def_function
  from tensorflow.python.eager import executor
  from tensorflow.python.framework import errors
  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 math_ops
  from tensorflow.python.ops import variables
  from tensorflow.python.platform import test
  from tensorflow.python.training import coordinator
  from tensorflow.python.training import server_lib
label_desc: Use image node_id 12 for calling the DynamicClusterTest obj's underlying member method code with example usage: obj.testFunctionRegisteredAndRemoved() and returns: math_ops