class_docstr: Tests mle losses.
      
docstr: Tests `sequence_sigmoid_cross_entropy`.
          
code: def test_sequence_sigmoid_cross_entropy(self):
      """Tests `sequence_sigmoid_cross_entropy`."""
      self._test_sequence_loss(
          tx.losses.sequence_sigmoid_cross_entropy,
          self._one_hot_labels,
          self._logits,
          self._sequence_length,
      )
  
      self._test_sequence_loss(
          tx.losses.sequence_sigmoid_cross_entropy,
          self._one_hot_labels[:, :, 0],
          self._logits[:, :, 0],
          self._sequence_length,
      )
  
      labels = tf.placeholder(dtype=tf.int32, shape=None)
      loss = tx.losses.sequence_sigmoid_cross_entropy(
          logits=self._logits[:, :, 0],
          labels=tf.cast(labels, tf.float32),
          sequence_length=self._sequence_length,
      )
      with self.test_session() as sess:
          rank = sess.run(
              tf.rank(loss),
              feed_dict={
                  labels: np.ones([self._batch_size, self._max_time])
              },
          )
          self.assertEqual(rank, 0)
  
file_path: texar/tests/losses/mle_losses_test.py
imports: import numpy
  import tensorflow
  import texar.tf
label_desc: Use image node_id 5 for calling the MLELossesTest obj's underlying member method code with example usage: obj.test_sequence_sigmoid_cross_entropy() without return types