protected abstract Task <SignatureHelpItems> GetItemsWorkerAsync(Document document, int position, SignatureHelpTriggerInfo triggerInfo, CancellationToken cancellationToken);
protected async Task <List <Tuple <Document, IEnumerable <SignatureHelpItem> > > > GetItemsForRelatedDocuments(Document document, IEnumerable <DocumentId> relatedDocuments, int position, SignatureHelpTriggerInfo triggerInfo, CancellationToken cancellationToken)
{
var supportedPlatforms = new List <Tuple <Document, IEnumerable <SignatureHelpItem> > >();
foreach (var relatedDocumentId in relatedDocuments)
{
var relatedDocument = document.Project.Solution.GetDocument(relatedDocumentId);
var semanticModel = await relatedDocument.GetSemanticModelForSpanAsync(new TextSpan(position, 0), cancellationToken).ConfigureAwait(false);
var result = await GetItemsWorkerAsync(relatedDocument, position, triggerInfo, cancellationToken).ConfigureAwait(false);
supportedPlatforms.Add(Tuple.Create(relatedDocument, result != null ? result.Items : SpecializedCollections.EmptyEnumerable <SignatureHelpItem>()));
}
return(supportedPlatforms);
}