class_docstr: Dummy univariate ranking network with constant scoring function.
class_docstr_tok: ["Dummy","univariate","ranking","network","with","constant","scoring","function","."]
code: def score(
      self, context_features=None, example_features=None, training=True
  ):
      large_batch_size = tf.shape(example_features["utility"])[0]
      return tf.ones(shape=(large_batch_size, 1))
  
imports: from absl.testing import parameterized
  import tensorflow
  from google.protobuf import text_format
  from tensorflow_ranking.python import data
  from tensorflow_ranking.python.keras import feature
  from tensorflow_ranking.python.keras import losses
  from tensorflow_ranking.python.keras import metrics
  from tensorflow_ranking.python.keras import model
  from tensorflow_ranking.python.keras import network
  from tensorflow_serving.apis import input_pb2
label_desc: Use image node_id 1 for calling the _DummyUnivariateRankingNetwork obj's underlying member method code with example usage: obj.score(context_features, example_features, training) and returns: tf