    def _gen_exec_key(self, shape):
        """rendering shape info"""
        return self.exec_key_template.render(
            x_dim0=shape[0],
            x_dim1=shape[1] * shape[2],
            x_dim2=shape[2],
        ).replace("\n", "")
rendering shape info
python/aitemplate/compiler/ops/vision_ops/nms/efficient_nms.py