@Nullable
    public static Object get(ClientRequestContext ctx, String name) {
        requireNonNull(ctx, "ctx");
        requireNonNull(name, "name");
        final Map<String, Object> attrs = ctx.attr(KEY);
        if (attrs == null) {
            return null;
        }
        return attrs.get(name);
    }
Returns the {@link RequestAttribute} value associated with the name.
spring/spring6/src/main/java/com/linecorp/armeria/spring/client/RequestAttributeAccess.java