// Copyright (c) Microsoft. All Rights Reserved. Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
/// <param name="expectedDescriptionOrNull">If this is null, the Description for the item is ignored.</param>
/// <param name="usePreviousCharAsTrigger">Whether or not the previous character in markup should be used to trigger IntelliSense for this provider. If false, invokes it through the invoke IntelliSense command.</param>
/// <param name="checkForAbsence">If true, checks for absence of a specific item (or that no items are returned from this CompletionProvider)</param>