Whether to encourage register method instead of namespace lookup.

[coady]

Opening this for comments on @multimethod vs @<name>.register.

This project pre-dates Python 3: type hints, mypy, and functools.singledispatch. At the time it seemed natural to register methods based on function name, which requires stack frame support to find a previously created multimethod. And there's strong precedence for it in languages with native multiple dispatch.

singledispatch has set a different precedent with explicit register methods on existing objects. Although this author doesn't particularly like using _ as a name, maybe conforming is more important now since it's established in the standard library.

Another compelling reason is that mypy raises already defined errors that have to be suppressed through configuration when using @multimethod.

[coady]

Added in 23589d3 to multidispatch.