public override async Task <Compilation> TransformCompilationAsync(Compilation oldCompilation, CancellationToken cancellationToken)
{
var syntaxTrees = new List <SyntaxTree>(capacity: _state.DocumentIds.Count);
foreach (var documentState in _state.OrderedDocumentStates)
{
cancellationToken.ThrowIfCancellationRequested();
syntaxTrees.Add(await documentState.GetSyntaxTreeAsync(cancellationToken).ConfigureAwait(false));
}
return(oldCompilation.RemoveAllSyntaxTrees().AddSyntaxTrees(syntaxTrees));
}