class_docstr: Stub for VariableSpec to simplify tests in np/jax backends.
code: def from_value(cls, variable):
      return cls(
          variable.shape,
          variable.dtype,
          variable.trainable,
          variable.name,
      )
  
imports: import collections
  from absl.testing import parameterized
  import numpy
  import tensorflow.compat.v2
  from tensorflow_probability.python.distributions import deterministic
  from tensorflow_probability.python.distributions import half_cauchy
  from tensorflow_probability.python.distributions import joint_distribution_auto_batched
  from tensorflow_probability.python.distributions import normal
  from tensorflow_probability.python.internal import nest_util
  from tensorflow_probability.python.internal import test_util
  from tensorflow.python.util import nest
label_desc: Use image node_id 2 for calling the VariableSpec obj's underlying member method code with example usage: obj.from_value(cls, variable) and returns: cls