S - 仕様型への自己参照 public static interface WebTestClient.RequestHeadersUriSpec<S extends WebTestClient.RequestHeadersSpec<S>> extends WebTestClient.UriSpec<S>, WebTestClient.RequestHeadersSpec<S>
uri, uri, uri, uriaccept, acceptCharset, attribute, attributes, cookie, cookies, exchange, header, headers, ifModifiedSince, ifNoneMatch