public BodyPartBuilder content(Path path) {
        requireNonNull(path, "path");
        return content(StreamMessage.of(path));
    }
Adds the specified {@link Path} as a body part content.
The default buffer size({@code 8192}) is used to create a buffer and the buffer is used to read data from
the {@link Path}.
core/src/main/java/com/linecorp/armeria/common/multipart/BodyPartBuilder.java