class_docstr: Tests correctness of the floor transformation.
code: def setUp(self):
      self._rng = np.random.RandomState(42)
  
imports: import numpy
  import tensorflow.compat.v2
  from tensorflow_probability.python.bijectors import bijector_test_util
  from tensorflow_probability.python.bijectors import softfloor
  from tensorflow_probability.python.internal import tensorshape_util
  from tensorflow_probability.python.internal import test_util
  from tensorflow_probability.python.math.gradient import value_and_gradient
label_desc: Use image node_id 1 for calling the _SoftFloorBijectorBase obj's underlying member method code with example usage: obj.setUp() without return types