pkgs.appimageTools.wrapType2.extendDrvArgs

The following is the current implementation of this function.

finalAttrs: args: {
      contents = extract (
        lib.filterAttrs (
          key: value:
          builtins.elem key [
            "pname"
            "version"
            "src"
          ]
        ) finalAttrs
      );

      # passthru src to make nix-update work
      # hack to keep the origin position (unsafeGetAttrPos)
      passthru =
        lib.pipe finalAttrs [
          lib.attrNames
          (lib.remove "src")
          (removeAttrs finalAttrs)
        ]
        // args.passthru or { };
    }