Function checkKey

src/app/assets/javascript/GreaseMonkeyAPI.js:32–36

(key, funcName)

    }
    
    function checkKey(key, funcName) {
        if (typeof key !== "string") {
          throw new Error(`${funcName} requires the first parameter to be of type string, not '${typeof key}'`);
        }
    }
    
    function GM_setValue(key, value) {
        checkKey(key, "GM_setValue");