docs: @Override
      public String getIconClassName() {
          // Oh the fun of somebody adding a legacy way of referencing images into 2.0 code
          String pattern = getIconFilePathPattern();
          if (pattern != null) {
              // here we go with the dance of the IconSet's
              String path = pattern.replace(":size", "24x24"); // we'll strip the icon-md to get the class name
              if (path.indexOf('/') == -1) {
                  // this one is easy... too easy... also will never happen
                  return IconSet.toNormalizedIconNameClass(path);
              }
              if (Jenkins.RESOURCE_PATH.length() > 0 && path.startsWith(Jenkins.RESOURCE_PATH)) {
                  // will to live falling
                  path = path.substring(Jenkins.RESOURCE_PATH.length());
              }
              Icon icon = IconSet.icons.getIconByUrl(path);
              if (icon != null) {
                  return icon.getClassSpec().replaceAll("\\s*icon-md\\s*", " ").replaceAll("\\s+", " ");
              }
          }
          return null;
      }