class_docstr: Encode an audio clip to WAV.
  
  This function is thread-safe and exhibits good parallel performance.
  
  Arguments:
    audio: A numpy array of shape `[samples, channels]`.
    samples_per_second: A positive `int`, in Hz.
  
  Returns:
    A bytestring with WAV-encoded data.
code: def __init__(self):
      super().__init__()
      self._audio_placeholder = None
      self._samples_per_second_placeholder = None
      self._encode_op = None
  
file_path: tensorboard/tensorboard/util/encoder.py
imports: import numpy
  from tensorboard.util import op_evaluator
label_desc: Use image node_id 1 to create a new _TensorFlowWavEncoder object from inherited base classes: op_evaluator with example: obj = _TensorFlowWavEncoder()