docs: public static boolean handleIfMatch(final String ifMatch, final List<ETag> etags, boolean allowWeak) {
          if (ifMatch == null) {
              return true;
          }
          if (ifMatch.equals("*")) {
              return true; //todo: how to tell if there is a current entity for the request
          }
          List<ETag> parts = parseETagList(ifMatch);
          for (ETag part : parts) {
              if (part.isWeak() && !allowWeak) {
                  continue;
              }
              for (ETag tag : etags) {
                  if (tag != null) {
                      if (tag.isWeak() && !allowWeak) {
                          continue;
                      }
                      if (tag.getTag().equals(part.getTag())) {
                          return true;
                      }
                  }
              }
          }
          return false;
      }