code: public static final ULocale getFunctionalEquivalent(String keyword,
                                                          ULocale locID,
                                                          boolean isAvailable[]) {
          return ICUResourceBundle.getFunctionalEquivalent(BASE, ICUResourceBundle.ICU_DATA_CLASS_LOADER, RESOURCE,
                                                           keyword, locID, isAvailable, true);
      }
docs: <strong>[icu]</strong> Returns the functionally equivalent locale for the given
  requested locale, with respect to given keyword, for the
  collation service.  If two locales return the same result, then
  collators instantiated for these locales will behave
  equivalently.  The converse is not always true; two collators
  may in fact be equivalent, but return different results, due to
  internal details.  The return result has no other meaning than
  that stated above, and implies nothing as to the relationship
  between the two locales.  This is intended for use by
  applications who wish to cache collators, or otherwise reuse
  collators when possible.  The functional equivalent may change
  over time.  For more information, please see the <a
  href="http://userguide.icu-project.org/locale#TOC-Locales-and-Services">
  Locales and Services</a> section of the ICU User Guide.
  @param keyword a particular keyword as enumerated by
  getKeywords.
  @param locID The requested locale
  @param isAvailable If non-null, isAvailable[0] will receive and
  output boolean that indicates whether the requested locale was
  'available' to the collation service. If non-null, isAvailable
  must have length &gt;= 1.
  @return the locale