chore: cleanup (#35)

Signed-off-by: Wouter Termont <wouter.termont@ugent.be>

Author: termontwouter

packages/css/src/identity/configuration/InMemoryJwksKeyHolder.ts

@@ -2,7 +2,6 @@ import type { KeyValueStorage, Representation, ResourceIdentifier } from "@solid
 import { AccessMap, getLoggerFor, InternalServerError, JwkGenerator, NotFoundHttpError } from "@solid/community-server";
 import { JWTPayload, decodeJwt, createRemoteJWKSet, jwtVerify, JWTVerifyOptions } from "jose";
 import { httpbis, type SigningKey, type Request as SignRequest } from 'http-message-signatures';
-import { isString } from '../util/StringGuard';
 import fetch from 'cross-fetch';
 import type { Fetcher } from "../util/fetch/Fetcher";
 import crypto from 'node:crypto';
@@ -338,3 +337,7 @@ export class UmaClient {
     });
   }
 }
+
+function isString(value: any): value is string {
+  return typeof value === 'string' || value instanceof String;
+}