Returns a string (number or name to display) matching the
given code constant.
Note that the string returned depends completely on the
locale's calendar. It is not predictable if the string will be
numeric or a name, or if in case it retuns a numeric string
how many digits that will have. For example, a short year
display string will normally be two digits with a Gregorian
calendar, but with a Jewish calendar it will have three
digits.
One of NativeNumberMode.
This argument designates the basic transliteration mode as
if specified for the year representation. However, depending
on the locale, different conversions for year and month, for
example, may be chosen internally. This is beyond the user's
control and depends on locale specific conventions of how a
date is assembled.
