code: def test_collapse_mixture_of_tastes(self):
      predictions = [
          np.array([1.0, 2.0, 3.0, 4.0], dtype=np.float32),
          np.array([4.0, 3.0, 2.0, 1.0], dtype=np.float32),
          np.array([3.0, 4.0, 1.0, 2.0], dtype=np.float32),
      ]
  
      collapsed_predictions = collapse_mixture_of_tastes(
          tastes_predictions=predictions, tastes_attentions=None
      ).eval(session=self.session)
  
      expected_predictions = np.array(
          [[4.0, 4.0, 3.0, 4.0]], dtype=np.float32
      )
      self.assertTrue(
          (collapsed_predictions == expected_predictions).all()
      )
  
file_path: tensorrec/test/test_recommendation_graphs.py
imports: import numpy
  import tensorflow
  import scipy.sparse
  from unittest import TestCase
  from tensorrec.prediction_graphs import CosineSimilarityPredictionGraph
  from tensorrec.recommendation_graphs import project_biases, split_sparse_tensor_indices, bias_prediction_dense, bias_prediction_serial, densify_sampled_item_predictions, rank_predictions, collapse_mixture_of_tastes, predict_similar_items
  from tensorrec.session_management import get_session
label_desc: Use image node_id 8 for calling the RecommendationGraphsTestCase obj's underlying member method code with example usage: obj.test_collapse_mixture_of_tastes() without return types