private static Microsoft.CodeAnalysis.Solution OpenSolution()
{
var filePath = Path.GetFullPath(Path.Combine(GetBaseDirectory(), "..", "..", "..", "..", "AsyncGenerator.sln"));
var workspace = AsyncCodeGenerator.CreateWorkspace(null);
return(AsyncCodeGenerator.OpenSolution(workspace, filePath, ImmutableArray <Predicate <string> > .Empty, Logger).GetAwaiter().GetResult());
}