code: function(textModel) {
  			if (this._model) {
  				this._model.removeEventListener("Changed", this._listener.onChanged); //$NON-NLS-0$
  			}
  			this._model = textModel;
  			if (this._model) {
  				this._model.addEventListener("Changed", this._listener.onChanged); //$NON-NLS-0$
  			}
  		}
docs: Sets the text model of the annotation model.  The annotation
  model listens for changes in the text model to update and remove
  annotations that are affected by the change.
  
  @param {orion.editor.TextModel} textModel the text model.
  
  @see orion.editor.AnnotationModel#getTextModel