code: def testLoadFastgenNsynth(self, batch_size):
      with tf.Graph().as_default():
          net = fastgen.load_fastgen_nsynth(batch_size=batch_size)
          self.assertEqual(net["X"].shape, (batch_size, 1))
          self.assertEqual(net["encoding"].shape, (batch_size, 16))
          self.assertEqual(net["predictions"].shape, (batch_size, 256))
  
file_path: magenta/magenta/models/nsynth/wavenet/fastgen_test.py
imports: import os
  from absl.testing import parameterized
  import librosa
  from magenta.models.nsynth.wavenet import fastgen
  import numpy
  import tensorflow.compat.v1
label_desc: Use image node_id 1 for calling the FastegenTest obj's underlying member method code with example usage: obj.testLoadFastgenNsynth(batch_size) without return types