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$ git ls-tree d0492b36
100644 blob a0423896973644771497bdc03eb99d5281615b51 file.txt
-$ git cat-file commit a0423896
+$ git cat-file blob a0423896
hello world!
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$ git cat-file -t 513feba2
blob
$ git cat-file blob 513feba2
+hello world!
hello world, again
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