protected void insertXFrameOptionsHeader(final HttpServletResponse httpServletResponse,
                                             final HttpServletRequest httpServletRequest) {
        insertXFrameOptionsHeader(httpServletResponse, httpServletRequest, this.xframeOptions);
    }
Insert content security policy header.

@param httpServletResponse the http servlet response
@param httpServletRequest  the http servlet request
core/cas-server-core-web-api/src/main/java/org/apereo/cas/web/support/filters/ResponseHeadersEnforcementFilter.java