make sample truly random, sort by string length

corpus.json.gz

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:4c42c4208d9bb36c9e513551404f0cecc595b141cf431b982422b36fa1d2fb90
-size 1283932
+oid sha256:020020c236a93dbb4d6bfbc7407ef91a9e344721a95a1ae3149b6e35554ca110
+size 1455486