class_docstr: A collection of decoder tests. This class should be inherited together with
  `tf.test.TestCase`.
class_docstr_tok: ["A","collection","of","decoder","tests",".","This","class","should","be","inherited","together","with","`","tf.test.TestCase","`","."]
code: def __init__(self):
      self.batch_size = 4
      self.sequence_length = 16
      self.input_depth = 10
      self.vocab_size = 100
      self.max_decode_length = 20
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from __future__ import unicode_literals
  import tensorflow
  import numpy
  from seq2seq.decoders import BasicDecoder, AttentionDecoder, AttentionLayerDot
  from seq2seq.decoders import beam_search_decoder
  from seq2seq.inference import beam_search
  from seq2seq.contrib.seq2seq import helper
label_desc: Use image node_id 1 to create a new DecoderTests object from inherited base classes: object with example: obj = DecoderTests()