def METHOD_NAME(self):
    content_length = int(self.headers.get('content-length', 0))
    data = self.rfile.read(content_length)
    m = self.match("/r/insights/v1/systems")
    if m:
        s = json.loads(data)
        s["unregistered_at"] = None
        s["account_number"] = "123456"
        print(s)
        systems[s["machine_id"]] = s
        self.send_response(200)
        self.end_headers()
        self.wfile.write(data)
        return
    m = self.match("/r/insights/uploads/([^/])+")
    if m:
        self.send_response(200)
        self.end_headers()
        self.wfile.write(b'{ "reports": [ "foo", "bar" ] }\n')
        return
    self.send_response(404)
    self.end_headers()