command for check unitypackage contents
$ go get github.com/JINZO631/unipkg
$ unipkg test.unitypackage
4b136c785493a53499db74999ca30791 Assets/Files/FileA.prefab
7a61a0b7381335a43a34180470922a17 Assets/Files
a5832b8ae9bb63745b67503cc08a3dde Assets/Files/FileB.prefab