class_docstr: This class represents an audio frame. The data is a numpy.ndarray.
  
  Args:
      sample_rate (`int`):
          The audio sample rate in Hz.
code: def __str__(self):
      return (
          "AudioFrame"
          + " shape="
          + str(self.shape)
          + " sample_rate="
          + str(self.sample_rate)
          + " timestamp="
          + str(self.timestamp)
          + " layout="
          + self._layout
      )
  
file_path: towhee/towhee/types/audio_frame.py
imports: import numpy
label_desc: Use image node_id 3 for calling the AudioFrame obj's underlying member method code with example usage: obj.__str__() and returns: unknown