code: public void delete(String name) throws IOException {
          if (name.equalsIgnoreCase(REQUIRE)) {
              require = -1;
          } else if (name.equalsIgnoreCase(INHIBIT)) {
              inhibit = -1;
          } else {
            throw new IOException("Attribute name not recognized by " +
                                  "CertAttrSet:PolicyConstraints.");
          }
          encodeThis();
      }
docs: Delete the attribute value.