function assertListValues(list, values) {
    const listValues = [...list.values()];
    assert.deepStrictEqual(listValues, values);
}
Check that the contents of the list match the values of the array.
@param {LinkedList} list The list to check 
@param {Array} values An array of values that should match.
@throws {AssertionError} If the values in the list don't match the
     values in the array.