private QilNode CompileRootExpression(XslNode applyTmpls)
{
// Compile start apply-templates call
CheckSingletonFocus();
_singlFocus.SetFocus(SingletonFocusType.InitialContextNode);
QilNode result = GenerateApply(_compiler.Root, applyTmpls);
_singlFocus.SetFocus(null);
return _f.DocumentCtor(result);
}