code: public String getShortName(long instant, Locale locale) {
          if (locale == null) {
              locale = Locale.getDefault();
          }
          String nameKey = getNameKey(instant);
          if (nameKey == null) {
              return iID;
          }
          String name;
          NameProvider np = getNameProvider();
          if (np instanceof DefaultNameProvider) {
              name = ((DefaultNameProvider) np).getShortName(locale, iID, nameKey, isStandardOffset(instant));
          } else {
              name = np.getShortName(locale, iID, nameKey);
          }
          if (name != null) {
              return name;
          }
          return printOffset(getOffset(instant));
      }
docs: Gets the short name of this datetime zone suitable for display using
  the specified locale.
  <p>
  If the name is not available for the locale, then this method returns a
  string in the format <code>[+-]hh:mm</code>.
  
  @param instant  milliseconds from 1970-01-01T00:00:00Z to get the name for
  @param locale  the locale to get the name for
  @return the human-readable short name in the specified locale