code: public Optional<SoyMsgBundle> resolve(final Optional<Locale> locale) throws IOException {
          if (!locale.isPresent()) {
              return Optional.absent();
          }
  
          synchronized (msgBundles) {
              SoyMsgBundle soyMsgBundle = null;
              if (isHotReloadModeOff()) {
                  soyMsgBundle = msgBundles.get(locale.get());
              }
              if (soyMsgBundle == null) {
                  soyMsgBundle = createSoyMsgBundle(locale.get());
                  if (soyMsgBundle == null) {
                      soyMsgBundle = createSoyMsgBundle(new Locale(locale.get().getLanguage()));
                  }
  
                  if (soyMsgBundle == null && fallbackToEnglish) {
                      soyMsgBundle = createSoyMsgBundle(Locale.ENGLISH);
                  }
  
                  if (soyMsgBundle == null) {
                      return Optional.absent();
                  }
  
                  if (isHotReloadModeOff()) {
                      msgBundles.put(locale.get(), soyMsgBundle);
                  }
              }
  
              return Optional.fromNullable(soyMsgBundle);
          }
      }
docs: Based on a provided locale return a SoyMsgBundle file.
  
  If a passed in locale object is "Optional.absent()",
  the implementation will return Optional.absent() as well
  @param locale - maybe locale
  @return maybe soy msg bundle