web/src/main/java/org/springframework/security/web/server/csrf/CsrfServerLogoutHandler.java
@Override
	public Mono<Void> logout(WebFilterExchange exchange, Authentication authentication) {
		return this.csrfTokenRepository.saveToken(exchange.getExchange(), null);
	}
@Override
	public Mono<Void> logout(WebFilterExchange exchange, Authentication authentication) {
		return this.csrfTokenRepository.saveToken(exchange.getExchange(), null);
	}
Clears the {@link CsrfToken}

@param exchange the exchange
@param authentication the {@link Authentication}
@return A completion notification (success or error)