@Override
  protected boolean checkPrerequisites(ServletRequest servletRequest) {
    boolean retVal = false;
    if (null == servletRequest.getAttribute(AbstractSecurityHeaderFilter.DENY_HEADER_OVERRIDES_FLAG)) {
      retVal = true;
    } else {
      servletRequest.removeAttribute(AbstractSecurityHeaderFilter.DENY_HEADER_OVERRIDES_FLAG);
    }
    return retVal;
  }
AmbariServerSecurityHeaderFilter adds security-related headers to HTTP response messages for Ambari Server UI
ambari-server/src/main/java/org/apache/ambari/server/security/AmbariServerSecurityHeaderFilter.java