public static final Function<String,Boolean> isCalendar(final String pattern, final Locale locale) {
        return new IsCalendar(pattern, locale);
    }
public static final Function < String , Boolean > isCalendar ( final String pattern , final Locale locale ) { return new IsCalendar ( pattern , locale ) ; }
<p>
Checks whether the target {@link String} represents a {@link Calendar} or not.
If it returns true, {@link FnString#toCalendar(String, Locale)} can be called
safely.
</p>
<p>
Pattern format is that of <tt>java.text.SimpleDateFormat</tt>.
</p>

@param pattern the pattern to be used.
@param locale the locale which will be used for parsing month names
@return true if the target {@link String} represents a {@link Calendar},
false otherwise