convert content URI to FileUpload

Question

I get content URI from getContent and I want to convert it to FileUpload

  object upload : FileUpload(mimetype) {
    override fun contentLength(): Long {
      TODO("return contentLength here")
    }
    override fun fileName(): String? {
      TODO("return fileName to use in the multipart request here")
    }
    override fun writeTo(sink: BufferedSink) {
      TODO("write the data here")
    }
  }