@UnstableApi
    static MultipartFile of(String name, String filename, Path path, HttpHeaders headers) {
        requireNonNull(name, "name");
        requireNonNull(filename, "filename");
        requireNonNull(path, "path");
        requireNonNull(headers, "headers");
        return new DefaultMultipartFile(name, filename, path, headers);
    }
Creates a new {@link MultipartFile}.
@param name the name parameter of the {@code "content-disposition"}
@param filename the filename parameter of the {@code "content-disposition"}
                header.
@param path the path that stores the {@link BodyPart#content()}.
@param headers HTTP part headers.
core/src/main/java/com/linecorp/armeria/common/multipart/MultipartFile.java