docs: private void constructContentMapper() {
          // Initialize the request resolver
          String contentMapperClassName = getParam(INIT_CONTENT_MAPPER_CLASS_NAME);
          Logger.getLogger(getClass()).debug("WebDAV Servlet content mapper class name = " + contentMapperClassName);
          if (contentMapperClassName == null) {
              this.contentMapper = new DefaultContentMapper();
          } else {
              try {
                  Class<? extends ContentMapper> clazz = Class.forName(contentMapperClassName).asSubclass(ContentMapper.class);
                  this.contentMapper = clazz.newInstance();
              } catch (Exception ex) {
                  throw new IllegalStateException(ex);
              }
          }
          Logger.getLogger(getClass()).debug("WebDAV Servlet using content mapper class = " + contentMapper.getClass().getName());
          this.contentMapper.initialize(getServletContext());
      }