code: def test_backs_off_to_trivial_bracket(self):
      dtype_info = np.finfo(np.float32)
      low, high = self.evaluate(
          root_search.bracket_root(
              lambda x: np.nan * x, dtype=np.float32
          )
      )
      self.assertEqual(low, dtype_info.min)
      self.assertEqual(high, dtype_info.max)
  
imports: import numpy
  import scipy.optimize
  import tensorflow.compat.v1
  import tensorflow.compat.v2
  from tensorflow_probability.python.internal import samplers
  from tensorflow_probability.python.internal import special_math
  from tensorflow_probability.python.internal import test_util
  from tensorflow_probability.python.math import root_search
label_desc: Use image node_id 5 for calling the BracketRootTest obj's underlying member method code with example usage: obj.test_backs_off_to_trivial_bracket() without return types