docs: @Nonnull
    public PageViewExternalHTMLCleanser setServerPrefixPath (@Nonnull @Nonempty final String sServerPrefixPath)
    {
      ValueEnforcer.notEmpty (sServerPrefixPath, "ServerPrefixPath");
      ValueEnforcer.isTrue (sServerPrefixPath.endsWith ("/"), "ServerPrefixPath must end with a slash");
      m_sServerPrefixPath = sServerPrefixPath;
      return this;
    }