| # Copyright 2019 The LUCI Authors. All rights reserved. |
| # Use of this source code is governed under the Apache License, Version 2.0 |
| # that can be found in the LICENSE file. |
| |
| |
| class _EmptyLog(str): |
| """A special string object equal to the empty string that can be used to |
| distinguish logs with no lines and logs containing a single empty line. |
| """ |
| def __new__(cls): |
| return super(_EmptyLog, cls).__new__(cls, '') |
| |
| def __copy__(self): |
| return self |
| |
| def __deepcopy__(self, memo): |
| return self |
| |
| EMPTY_LOG = _EmptyLog() |
