code: def testSimpleShapes(self):
      a = np.random.rand(3)
      b = np.random.rand(3)
      dist = sigmoid_beta.SigmoidBeta(a, b, validate_args=True)
      self.assertAllEqual([], self.evaluate(dist.event_shape_tensor()))
      self.assertAllEqual([3], self.evaluate(dist.batch_shape_tensor()))
      self.assertEqual(tf.TensorShape([]), dist.event_shape)
      self.assertEqual(tf.TensorShape([3]), dist.batch_shape)
  
imports: import numpy
  from scipy import stats
  import tensorflow.compat.v2
  from tensorflow_probability.python.bijectors import invert
  from tensorflow_probability.python.bijectors import sigmoid
  from tensorflow_probability.python.distributions import beta
  from tensorflow_probability.python.distributions import sigmoid_beta
  from tensorflow_probability.python.distributions import transformed_distribution
  from tensorflow_probability.python.distributions.internal import statistical_testing
  from tensorflow_probability.python.internal import assert_util
  from tensorflow_probability.python.internal import test_util
label_desc: Use image node_id 1 for calling the SigmoidBetaTest obj's underlying member method code with example usage: obj.testSimpleShapes() without return types