src/transformers/models/jukebox/modeling_jukebox.py/JukeboxBottleneck/__init__
class JukeboxBottleneck:    def __init__(self, config, levels):
        super().__init__()
        self.levels = levels
        self.level_blocks = nn.ModuleList()
        for level in range(self.levels):
            self.level_blocks.append(JukeboxBottleneckBlock(config))