NullTime provides a time.Time that may be null.
Copyright (c) 2011-2013, 'pq' Contributors
Portions Copyright (C) 2011 Blake Mizerany
Modified by Kirill Danshin k@guava.by (c) 2016
NullTime provides a time.Time that may be null.
Copyright (c) 2011-2013, 'pq' Contributors
Portions Copyright (C) 2011 Blake Mizerany
Modified by Kirill Danshin k@guava.by (c) 2016