code: def testFlattenSampleTransformations(self, batch_shape):
      model = targets.VectorModel(
          TestStructuredModel(), flatten_sample_transformations=True
      )
  
      x_init = tf.zeros(batch_shape + model.event_shape, model.dtype)
      first_moment_transform = model.sample_transformations[
          "first_moment"
      ]
      first_moment = first_moment_transform(x_init)
      self.assertAllEqual(
          batch_shape + model.event_shape, first_moment.shape
      )
      self.assertAllEqual(
          model.event_shape,
          first_moment_transform.ground_truth_mean.shape,
      )
      self.assertAllEqual(
          model.event_shape,
          first_moment_transform.ground_truth_standard_deviation.shape,
      )
      self.assertAllEqual(
          model.event_shape,
          first_moment_transform.ground_truth_mean_standard_error.shape,
      )
      self.assertAllEqual(
          model.event_shape,
          first_moment_transform.ground_truth_standard_deviation_standard_error.shape,
      )
  
imports: from absl.testing import parameterized
  import numpy
  import tensorflow.compat.v2
  import tensorflow_probability
  from tensorflow_probability.python.internal import test_util
  from inference_gym import targets
  from inference_gym.internal import test_util
label_desc: Use image node_id 2 for calling the VectorModelTest obj's underlying member method code with example usage: obj.testFlattenSampleTransformations(batch_shape) without return types