func NewPackageLogger(repo, pkg string) Logger {
	return &packageLogger{p: capnslog.NewPackageLogger(repo, pkg)}
}
func NewPackageLogger(repo, pkg string) Logger {
	return &packageLogger{p: capnslog.NewPackageLogger(repo, pkg)}
}
// NewPackageLogger wraps "*capnslog.PackageLogger" that implements "Logger" interface.
//
// For example:
//
//  var defaultLogger Logger
//  defaultLogger = NewPackageLogger("go.etcd.io/etcd", "snapshot")
//