(undo-tree-save-format-version . 1)
"a9cf4f48127bf5b059eb1a62316494f673ba2e0e"
[nil nil nil nil (25197 28911 998836 170000) 0 nil]
([nil current ((1 . 3881) (t . 0)) nil (25197 28911 998832 92000) 0 nil])
nil