  def testSwitchEagerMode(self):
    if not context.executing_eagerly():
      return
    input_data = [1, 2, 3, 4]
    vf, vt = control_flow_ops.switch(input_data, False)
    self.assertAllEqual(vf, input_data)
    self.assertAllEqual(vt, [])
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.