code: def testIsSwitch(self):
      switch_false, _ = control_flow_ops.switch(1, True)
      switch = switch_false.op
      self.assertTrue(control_flow_util.IsSwitch(switch))
  
      ref_switch_false, _ = control_flow_ops.ref_switch(
          test_ops.ref_output(), True
      )
      ref_switch = ref_switch_false.op
      self.assertTrue(control_flow_util.IsSwitch(ref_switch))
  
      self.assertFalse(
          control_flow_util.IsSwitch(test_ops.int_output().op)
      )
  
imports: from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import test_ops
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import cond
  from tensorflow.python.ops import control_flow_ops
  from tensorflow.python.ops import control_flow_util
  from tensorflow.python.ops import gen_control_flow_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import while_loop
  from tensorflow.python.platform import test
label_desc: Use image node_id 1 for calling the ControlFlowUtilTest obj's underlying member method code with example usage: obj.testIsSwitch() without return types