class_docstr: GroupwiseRankingModel tests.
docstr: Test for group size = 1.
docstr_tok: ["Test","for","group","size","=","1","."]
code: def test_update_scatter_gather_indices_groupsize_1(self):
      """Test for group size = 1."""
      tf.random.set_seed(1)
      ranking_model = model._GroupwiseRankingModel(None, group_size=1)
      ranking_model._update_scatter_gather_indices(
          tf.convert_to_tensor(value=[[True, True, False]]),
          tf_estimator.ModeKeys.TRAIN,
          None,
      )
      self.assertEqual(
          ranking_model._feature_gather_indices.get_shape().as_list(),
          [1, 3, 1, 2],
      )
      self.assertEqual(
          ranking_model._indices_mask.get_shape().as_list(), [1, 3]
      )
      self.assertAllEqual(
          ranking_model._feature_gather_indices,
          [[[[0, 0]], [[0, 1]], [[0, 0]]]],
      )
      self.assertAllEqual(
          ranking_model._indices_mask, [[True, True, False]]
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  from absl.testing import parameterized
  import tensorflow
  from tensorflow import estimator
  from tensorflow_ranking.python import feature
  from tensorflow_ranking.python import head
  from tensorflow_ranking.python import losses
  from tensorflow_ranking.python import model
label_desc: Use image node_id 1 for calling the GroupwiseRankingModelTest obj's underlying member method code with example usage: obj.test_update_scatter_gather_indices_groupsize_1() without return types