code: function jwtSignRS256(payload, privateKey) {
      var signaturePayload = JWT_RS256_HEADER + '.' + toBase64URL(JSON.stringify(payload));
  
      var rs256Signer = crypto.createSign('RSA-SHA256');
      rs256Signer.update(signaturePayload);
      var signature = toBase64URL(rs256Signer.sign(privateKey));
  
      return signaturePayload + '.' + signature;
  }
docs: Creates a JSON Web Token signed with RS256 (SHA256 + RSA)
  Only this specific operation is needed so it's implemented here
  instead of depending on jsonwebtoken.
  
  @param {Object} payload The payload to include in the generated token
  @param {String} privateKey Private key in PEM format for signing the token
  @return {String} The generated and signed token