docs: public @CheckForNull
      ClassStats getClassStats(@DottedClassName String className) {
          if (hasClassStats) {
              return null;
          }
          String packageName;
          int lastDot = className.lastIndexOf('.');
          if (lastDot < 0) {
              packageName = "";
          } else {
              packageName = className.substring(0, lastDot);
          }
          PackageStats stat = getPackageStats(packageName);
          return stat.getClassStatsOrNull(className);
      }