code: public void set(String name, Object obj) throws IOException {
          if (name.equalsIgnoreCase(KEY_ID)) {
              if (!(obj instanceof KeyIdentifier)) {
                throw new IOException("Attribute value should be of " +
                                      "type KeyIdentifier.");
              }
              id = (KeyIdentifier)obj;
          } else if (name.equalsIgnoreCase(AUTH_NAME)) {
              if (!(obj instanceof GeneralNames)) {
                throw new IOException("Attribute value should be of " +
                                      "type GeneralNames.");
              }
              names = (GeneralNames)obj;
          } else if (name.equalsIgnoreCase(SERIAL_NUMBER)) {
              if (!(obj instanceof SerialNumber)) {
                throw new IOException("Attribute value should be of " +
                                      "type SerialNumber.");
              }
              serialNum = (SerialNumber)obj;
          } else {
            throw new IOException("Attribute name not recognized by " +
                          "CertAttrSet:AuthorityKeyIdentifier.");
          }
          encodeThis();
      }
docs: Set the attribute value.