# Mixing positional and keyword arguments for `legend` handles and labels\...

\... is no longer valid. If passing *handles* and *labels* to `legend`,
they must now be passed either both positionally or both as keywords.

# Legend labels for `plot`

Previously if a sequence was passed to the *label* parameter of
[\~.Axes.plot]{.title-ref} when plotting a single dataset, the sequence
was automatically cast to string for the legend label. Now, if the
sequence length is not one an error is raised. To keep the old behavior,
cast the sequence to string before passing.