code: def test_interpolate_backward_differences_zeroth_order_is_unchanged(
      self, dtype
  ):
      backward_differences = tf.constant(
          np.random.normal(size=((bdf_util.MAX_ORDER + 3, 3))),
          dtype=dtype,
      )
      real_dtype = abs(backward_differences).dtype
      step_size_ratio = tf.constant(0.5, dtype=real_dtype)
      interpolated_backward_differences = (
          bdf_util.interpolate_backward_differences(
              backward_differences, bdf_util.MAX_ORDER, step_size_ratio
          )
      )
      self.assertAllClose(
          self.evaluate(backward_differences[0]),
          self.evaluate(interpolated_backward_differences[0]),
      )
  
file_path: probability/tensorflow_probability/python/math/ode/bdf_util_test.py
imports: from absl.testing import parameterized
  import numpy
  import tensorflow.compat.v2
  from tensorflow_probability.python.internal import test_util
  from tensorflow_probability.python.math.ode import bdf_util
label_desc: Use image node_id 3 for calling the BDFUtilTest obj's underlying member method code with example usage: obj.test_interpolate_backward_differences_zeroth_order_is_unchanged(dtype) without return types