private static IEnumerable <NameSyntax> StaticClasses(this SyntaxList <UsingDirectiveSyntax> usings)
{
foreach (UsingDirectiveSyntax usingDirective in usings.StaticUsings())
{
NameSyntax name = usingDirective.Name;
if (name != null)
{
yield return(name);
}
}
}
