docs: protected Collection<? extends GrantedAuthority> buildGrantedAuthorities(PortletRequest context) {
          Collection<String> portletUserRoles = getUserRoles(context);
          Collection<? extends GrantedAuthority> userGas = portletUserRoles2GrantedAuthoritiesMapper.getGrantedAuthorities(portletUserRoles);
  
          if (logger.isDebugEnabled()) {
              logger.debug("Portlet roles [" + portletUserRoles + "] mapped to Granted Authorities: [" + userGas + "]");
          }
          return userGas;
      }