    def build_vision_encoder(self):
        """build vision encoder
        Returns: (vision_encoder, clip_teacher). Each is a `nn.Module`.

        """
        encoder_name = self.config.model.vision_encoder.name
        logger.info(f"Build vision_encoder: {encoder_name}")
        if "vit" in encoder_name:
            vision_encoder = build_vit(self.config.model, add_pool_norm=False)
        else:
            raise ValueError(f"not implemented: {encoder_name}")
        return vision_encoder
build vision encoder
Returns: (vision_encoder, clip_teacher). Each is a `nn.Module`.
videomamba/video_mm/models/umt_qa.py