'Some classes may want to replace a hyphen for minus with the
proper unicode symbol (U+2212) for typographical correctness.
The default is to not replace it.
Note, if you use this method, e.g., in :meth:`format_data` or
call, you probably don\'t want to use it for
:meth:`format_data_short` since the toolbar uses this for
interactive coord reporting and I doubt we can expect GUIs
across platforms will handle the unicode correctly.  So for
now the classes that override :meth:`fix_minus` should have an
explicit :meth:`format_data_short` method'

def fix_minus(self, s):

    return s
