def _validate_sample_arg(self, x):
    """"""
    with tf.name_scope("validate_sample_arg"):
      x_ndims = (
          tf.rank(x) if tensorshape_util.rank(x.shape) is None else
          tensorshape_util.rank(x.shape))
      event_ndims = (
          tf.size(input=self.event_shape_tensor())
          if tensorshape_util.rank(self.event_shape) is None else
          tensorshape_util.rank(self.event_shape))
      batch_ndims = (
          tf.size(input=self._batch_shape_unexpanded)
          if tensorshape_util.rank(self.batch_shape) is None else
          tensorshape_util.rank(self.batch_shape))
      expected_batch_event_ndims = batch_ndims + event_ndims

      if (isinstance(x_ndims, int) and
          isinstance(expected_batch_event_ndims, int)):
        if x_ndims < expected_batch_event_ndims:
          raise NotImplementedError(
              "Broadcasting is not supported; too few batch and event dims "
              "(expected at least {}, saw {}).".format(
                  expected_batch_event_ndims, x_ndims))
        ndims_assertion = []
      elif self.validate_args:
        ndims_assertion = [
            assert_util.assert_greater_equal(
                x_ndims,
                expected_batch_event_ndims,
                message=("Broadcasting is not supported; too few "
                         "batch and event dims."),
                name="assert_batch_and_event_ndims_large_enough"),
        ]

      if (tensorshape_util.is_fully_defined(self.batch_shape) and
          tensorshape_util.is_fully_defined(self.event_shape)):
        expected_batch_event_shape = np.int32(
            tensorshape_util.concatenate(self.batch_shape, self.event_shape))
      else:
        expected_batch_event_shape = tf.concat(
            [
                self.batch_shape_tensor(),
                self.event_shape_tensor(),
            ], axis=0)

      sample_ndims = x_ndims - expected_batch_event_ndims
      if isinstance(sample_ndims, int):
        sample_ndims = max(sample_ndims, 0)
      if (isinstance(sample_ndims, int) and
          tensorshape_util.is_fully_defined(x.shape[sample_ndims:])):
        actual_batch_event_shape = np.int32(x.shape[sample_ndims:])
      else:
        sample_ndims = tf.maximum(sample_ndims, 0)
        actual_batch_event_shape = tf.shape(input=x)[sample_ndims:]

      if (isinstance(expected_batch_event_shape, np.ndarray) and
          isinstance(actual_batch_event_shape, np.ndarray)):
        if any(expected_batch_event_shape != actual_batch_event_shape):
          raise NotImplementedError("Broadcasting is not supported; "
                                    "unexpected batch and event shape "
                                    "(expected {}, saw {}).".format(
                                        expected_batch_event_shape,
                                        actual_batch_event_shape))
        # We need to set the final runtime-assertions to `ndims_assertion` since
        # its possible this assertion was created. We could add a condition to
        # only do so if `self.validate_args == True`, however this is redundant
        # as `ndims_assertion` already encodes this information.
        runtime_assertions = ndims_assertion
      elif self.validate_args:
        # We need to make the `ndims_assertion` a control dep because otherwise
        # TF itself might raise an exception owing to this assertion being
        # ill-defined, ie, one cannot even compare different rank Tensors.
        with tf.control_dependencies(ndims_assertion):
          shape_assertion = assert_util.assert_equal(
              expected_batch_event_shape,
              actual_batch_event_shape,
              message=("Broadcasting is not supported; "
                       "unexpected batch and event shape."),
              name="assert_batch_and_event_shape_same")
        runtime_assertions = [shape_assertion]
      else:
        runtime_assertions = []

      return runtime_assertions