src/transformers/models/perceiver/modeling_perceiver.py/PerceiverAudioPostprocessor/__init__
class PerceiverAudioPostprocessor:    def __init__(self, config: PerceiverConfig, in_channels: int, postproc_type: str = "patches") -> None:
        super().__init__()

        if postproc_type not in ("patches",):  # to be supported: 'conv', 'patches', 'pixels'
            raise ValueError("Invalid postproc_type!")

        # Architecture parameters:
        self.classifier = nn.Linear(in_channels, config.samples_per_patch)