code: public void set(String name, Object obj) throws IOException {
          if (!(obj instanceof Integer)) {
              throw new IOException("Attribute must be of type Integer.");
          }
          if (name.equalsIgnoreCase(VERSION)) {
              version = ((Integer)obj).intValue();
          } else {
              throw new IOException("Attribute name not recognized by " +
                                    "CertAttrSet: CertificateVersion.");
          }
      }
docs: Set the attribute value.