code: def test_requires_wav(self):
      data = np.array(1, np.float32, ndmin=3)
      with self.assertRaisesRegex(ValueError, "Unknown encoding"):
          self.audio("k488", data, 44100, encoding="pptx")
  
imports: import glob
  import os
  import numpy
  import tensorflow
  from tensorboard.compat import tf2
  from tensorboard.plugins.audio import metadata
  from tensorboard.plugins.audio import summary
  from tensorboard.util import tensor_util
label_desc: Use image node_id 13 for calling the SummaryBaseTest obj's underlying member method code with example usage: obj.test_requires_wav() without return types