code: protected boolean isSupportRefreshToken(OAuth2Request clientAuth) {
  		if (clientDetailsService != null) {
  			ClientDetails client = clientDetailsService.loadClientByClientId(clientAuth.getClientId());
  			return client.getAuthorizedGrantTypes().contains("refresh_token");
  		}
  		return this.supportRefreshToken;
  	}
docs: Is a refresh token supported for this client (or the global setting if
  {@link #setClientDetailsService(ClientDetailsService) clientDetailsService} is not set.
  
  @param clientAuth the current authorization request
  @return boolean to indicate if refresh token is supported