oauth2/oauth2-client/src/main/java/org/springframework/security/oauth2/client/web/reactive/function/client/ServletOAuth2AuthorizedClientExchangeFilterFunction.java
public static Consumer<Map<String, Object>> clientRegistrationId(String clientRegistrationId) {
		return attributes -> attributes.put(CLIENT_REGISTRATION_ID_ATTR_NAME, clientRegistrationId);
	}
public static Consumer<Map<String, Object>> clientRegistrationId(String clientRegistrationId) {
		return attributes -> attributes.put(CLIENT_REGISTRATION_ID_ATTR_NAME, clientRegistrationId);
	}
Modifies the {@link ClientRequest#attributes()} to include the {@link ClientRegistration#getRegistrationId()} to
be used to look up the {@link OAuth2AuthorizedClient}.

@param clientRegistrationId the {@link ClientRegistration#getRegistrationId()} to
be used to look up the {@link OAuth2AuthorizedClient}.
@return the {@link Consumer} to populate the attributes