code: def affine_mat(self)->AffineMatrix:
          "Get the affine matrix that will be applied by `refresh`."
          if self._affine_mat is None:
              self._affine_mat = torch.eye(3).to(self.device)
          return self._affine_maf affine_mat(self)->AffineMatrix:
          "Get the affine matrix that will be applied by `refresh`."
          if self._affine_mat is None:
              self._affine_mat = torch.eye(3).to(self.device)
          return self._affine_mat
docs: Get the affine matrix that will be applied by `refresh`.