Test examples in the given object's docstring (`f`), using `globs`
as globals. Optional argument `name` is used in failure messages.
If the optional argument `verbose` is true, then generate output
even if there are no failures.
`compileflags` gives the set of flags that should be used by the
Python compiler when running the examples. If not specified, then
it will default to the set of future-import flags that apply to
`globs`.
Optional keyword arg `optionflags` specifies options for the
testing and output. See the documentation for `testmod` for more
information.