class_docstr: Test for `sqe2seq.losses.sequence_mask`.
class_docstr_tok: ["Test","for","`","sqe2seq.losses.sequence_mask","`","."]
code: def setUp(self):
      super(CrossEntropySequenceLossTest, self).setUp()
      tf.logging.set_verbosity(tf.logging.INFO)
      self.batch_size = 4
      self.sequence_length = 10
      self.vocab_size = 50
  
file_path: seq2seq/seq2seq/test/losses_test.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from __future__ import unicode_literals
  from seq2seq import losses
  import tensorflow
  import numpy
label_desc: Use image node_id 1 for calling the CrossEntropySequenceLossTest obj's underlying member method code with example usage: obj.setUp() without return types