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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def output_channels(self):
 """Returns the number of output channels."""

    if callable(self._output_channels):
      self._output_channels = self._output_channels()
    # Channel must be integer.
    self._output_channels = int(self._output_channels)
    return self._output_channels