/// <summary>
 /// Implement to contribute <see cref="CompletionItem"/>'s and other details to a <see cref="CompletionList"/>
 /// </summary>
 public abstract Task ProvideCompletionsAsync(CompletionContext context);
 private static bool HasAnyItems(CompletionContext cc)
 {
     return(cc.Items.Count > 0 || cc.SuggestionModeItem != null);
 }