class HTTP::Client

def make_request_body(opts, headers)
  request_body =
    case
    when opts.body
      opts.body
    when opts.form
      form = HTTP::FormData.create opts.form
      headers[Headers::CONTENT_TYPE]   ||= form.content_type
      headers[Headers::CONTENT_LENGTH] ||= form.content_length
      form.to_s
    when opts.json
      body = MimeType[:json].encode opts.json
      headers[Headers::CONTENT_TYPE] ||= "application/json; charset=#{body.encoding.name}"
      body
    end
  if (auto_deflate = opts.feature(:auto_deflate))
    auto_deflate.deflate(headers, request_body)
  else
    request_body
  end
end