remove test4.txt
remove test2.txt
remove test1.txt
Revert "remove test1.txt"

This reverts commit cdea1671bec77b368ca7aecc08e64713fc6fad7d.
Revert "remove test2.txt"

This reverts commit 4f06a052ff3bb53f3352bbeccb5286cbc2f4262e.