text: import tensorflow as tf
  
  
  class Constant(object):
      TEMP_DIRECTORY = './tmp'
      NUM_TRIALS = 100
      VALIDATION_SET_SIZE = 0.08333
      # TODO: Change it to random and configurable.
      SEED = 42
      BATCH_SIZE = 128
      RNN_LAYERS = {
          'vanilla': tf.keras.layers.SimpleRNN,
          'gru': tf.keras.layers.GRU,
          'lstm': tf.keras.layers.LSTM
      }
  
      # Text
      VOCABULARY_SIZE = 20000
  