code: protected int getRefreshTokenValiditySeconds(OAuth2Request clientAuth) {
  		if (clientDetailsService != null) {
  			ClientDetails client = clientDetailsService.loadClientByClientId(clientAuth.getClientId());
  			Integer validity = client.getRefreshTokenValiditySeconds();
  			if (validity != null) {
  				return validity;
  			}
  		}
  		return refreshTokenValiditySeconds;
  	}
docs: The refresh token validity period in seconds
  
  @param clientAuth the current authorization request
  @return the refresh token validity period in seconds