function storagePushToSet([key, value]) {
    log('storagePushToSet', key, value);

    const item = getLocalStorageItem(key);
    const list = Array.isArray(item) ? item : [];

    if (list.indexOf(value) === -1) {
      list.push(value);
    }

    setLocalStorageItem(key, list);
  }
function storagePushToSet([key, value]) {
    log('storagePushToSet', key, value);

    const item = getLocalStorageItem(key);
    const list = Array.isArray(item) ? item : [];

    if (list.indexOf(value) === -1) {
      list.push(value);
    }

    setLocalStorageItem(key, list);
  }
function storagePushToSet ( [ key , value ] ) { log ( 'storagePushToSet' , key , value ) ; const item = getLocalStorageItem ( key ) ; const list = Array . isArray ( item ) ? item : [ ] ; if ( list . indexOf ( value ) === - 1 ) { list . push ( value ) ; } setLocalStorageItem ( key , list ) ; }
A Set is a list with only unique values. (No duplication.)
A Set is a list with only unique values . ( No duplication . )