When using the doctest module it is often
convenient to use the ELLIPSIS option, which allows you to use ... as a
wildcard. But you either have to setup the test runner to use this option, or
you must put #doctest: +ELLIPSIS on every example that uses this feature.
dtopt lets you enable this option globally from within a doctest, by doing:
>>> from dtopt import ELLIPSIS
(The options NORMALIZE_WHITESPACE and COMPARE are also available)
