code: def testNoneDimsWithDynamicRNN(self):
      with self.session(use_gpu=True, graph=tf.Graph()) as sess:
          batch_size = 4
          num_steps = 5
          input_dim = 6
          cell_size = 7
  
          cell = contrib_rnn.LSTMBlockCell(cell_size)
          x = tf.placeholder(tf.float32, shape=(None, None, input_dim))
  
          output, _ = tf.nn.dynamic_rnn(
              cell, x, time_major=True, dtype=tf.float32
          )
          sess.run(tf.global_variables_initializer())
          feed = {}
          feed[x] = np.random.randn(num_steps, batch_size, input_dim)
          sess.run(output, feed)
  
imports: import itertools
  from absl.testing import parameterized
  from magenta.contrib import rnn
  import numpy
  import tensorflow.compat.v1
label_desc: Use image node_id 1 for calling the LSTMBlockCellTest obj's underlying member method code with example usage: obj.testNoneDimsWithDynamicRNN() without return types