src/transformers/models/dpt/modeling_dpt.py/DPTNeck/__init__
class DPTNeck:    def __init__(self, config):
        super().__init__()
        self.config = config

        # postprocessing
        self.reassemble_stage = DPTReassembleStage(config)
        self.convs = nn.ModuleList()
        for channel in config.neck_hidden_sizes:
            self.convs.append(nn.Conv2d(channel, config.fusion_hidden_size, kernel_size=3, padding=1, bias=False))

        # fusion
        self.fusion_stage = DPTFeatureFusionStage(config)