code: public void revoke(User revoker, Enrollment enrollment, String reason) throws RevocationException, InvalidArgumentException {
          revokeInternal(revoker, enrollment, reason, false);
      }
docs: revoke one enrollment of user
  
  @param revoker    admin user who has revoker attribute configured in CA-server
  @param enrollment the user enrollment to be revoked
  @param reason     revoke reason, see RFC 5280
  @throws RevocationException
  @throws InvalidArgumentException