docs: public LdapNameBuilder add(String key, Object value) {
          Assert.hasText(key, "key must not be blank");
          Assert.notNull(key, "value must not be null");
  
          try {
              ldapName.add(new Rdn(key, value));
              return this;
          } catch (InvalidNameException e) {
              throw new org.springframework.ldap.InvalidNameException(e);
          }
      }