code: @Override
      public final FamilyDocument findByRootAndString(
              final RootDocument rootDocument, final String string) {
          final FamilyDocument familyDocument =
                  findByFileAndString(rootDocument.getFilename(), string);
          if (familyDocument == null) {
              return null;
          }
          final Family family = familyDocument.getGedObject();
          family.setParent(rootDocument.getGedObject());
          return familyDocument;
      }
docs: {@inheritDoc}