code: def testShapeWithPlaceholders(self):
      df = tf.Variable(self.dtype(2.0), shape=tf.TensorShape(None))
      loc = tf.Variable(
          self.dtype([0.0, 1.0]), shape=tf.TensorShape(None)
      )
      scale = tf.Variable(
          self.dtype([[1.0, 2.0]]), shape=tf.TensorShape(None)
      )
      skewness = tf.Variable(
          self.dtype([[0.75, 1.0], [1.0, 1.33]]).T,
          shape=tf.TensorShape(None),
      )
  
      dist = two_piece_student_t.TwoPieceStudentT(
          df=df,
          loc=loc,
          scale=scale,
          skewness=skewness,
          validate_args=True,
      )
      self.evaluate([v.initializer for v in dist.variables])
  
      # get_batch_shape should return an '<unknown>' tensor (graph mode only).
      self.assertEqual(dist.event_shape, ())
      self.assertEqual(dist.batch_shape, tf.TensorShape(None))
      self.assertAllEqual(self.evaluate(dist.event_shape_tensor()), [])
      self.assertAllEqual(
          self.evaluate(dist.batch_shape_tensor()), [2, 2]
      )
  
imports: from absl.testing import parameterized
  import numpy
  import tensorflow.compat.v2
  from tensorflow_probability.python.distributions import two_piece_student_t
  from tensorflow_probability.python.internal import test_util
  from tensorflow_probability.python.math import gradient
label_desc: Use image node_id 20 for calling the _TwoPieceStudentTTest obj's underlying member method code with example usage: obj.testShapeWithPlaceholders() without return types