func golang.org/x/tools/internal/versions.IsValid
2 uses
	golang.org/x/tools/internal/versions (current package)
		types.go#L27: 	if v := info.FileVersions[file]; IsValid(v) {
		versions.go#L47: func IsValid(x string) bool { return isValid(stripGo(x)) }
The pages are generated with Golds v0.7.6. (GOOS=linux GOARCH=amd64)