public OutliningTagger(ITextBuffer textBuffer, IBackgroundParser backgroundParser)
{
Contract.Requires <ArgumentNullException>(textBuffer != null, "textBuffer");
Contract.Requires <ArgumentNullException>(backgroundParser != null, "backgroundParser");
this.TextBuffer = textBuffer;
this.BackgroundParser = backgroundParser;
_outliningRegions = new List <ITagSpan <IOutliningRegionTag> >();
BackgroundParser.ParseComplete += HandleBackgroundParseComplete;
BackgroundParser.RequestParse(false);
}