multipart.swift

public func upload(parts: [Content], url: uploadUrl) throws -> Future<Response> {
	var b2Headers: [String: String] = ["Content-Type": "multipart/form-data; boundary=-123-"]
	b2Headers["Content-Length"] = // Err... We'll figure this out later

	let headers = HTTPHeaders(b2Headers.map { $0 })

	let request = Request(using: self.client.container)
	request.http.method = .POST
	request.http.headers = headers
	request.http.body = ""
	
	for part in parts {
		var appendPart = ""
		
		 if let file = part as File {
			appendPart.append("Content-Disposition: form-data; name=\(file.filename); filename=\(file.filename)\n")
			appendPart.append("Content-Type: \(file.contentType)\n\n")
			appendPart.append(data)
			
		}
		//also append to appendPart if it's not a File, idk it's pseudo code 
		request.http.body.append(appendPart)
	}
	
	request.http.url = uploadURL!

	return self.client.send(request)
}