public ContentStreamEngine(DocumentHandler _handler) {
this.documentHandler = _handler;
// ---- Graphics operators
registerOperatorProcessor("w", new SetLineWidth());
registerOperatorProcessor("cm", new Concatenate());
registerOperatorProcessor("CS", new SetStrokingColorSpace());
registerOperatorProcessor("cs", new SetNonStrokingColorSpace());
registerOperatorProcessor("d", new SetLineDashPattern());
registerOperatorProcessor("Do", new Invoke());