in src/panda.ts [7:25]
export function createCookie(user: User, privateKey: string): string {
let queryParams: string[] = [];
queryParams.push("firstName=" + user.firstName);
queryParams.push("lastName=" + user.lastName);
queryParams.push("email=" + user.email);
user.avatarUrl && queryParams.push("avatarUrl=" + user.avatarUrl);
queryParams.push("system=" + user.authenticatingSystem);
queryParams.push("authedIn=" + user.authenticatedIn.join(","));
queryParams.push("expires=" + user.expires.toString());
queryParams.push("multifactor=" + String(user.multifactor));
const combined = queryParams.join("&");
const queryParamsString = Buffer.from(combined).toString('base64');
const signature = sign(combined, privateKey);
return queryParamsString + "." + signature
}