src/vs/editor/contrib/gotoSymbol/browser/peek/referencesWidget.ts/DecorationsManager/_addDecorations
class DecorationsManager:	private _addDecorations(reference: FileReferences): void {
		if (!this._editor.hasModel()) {
			return;
		}
		this._callOnModelChange.add(this._editor.getModel().onDidChangeDecorations(() => this._onDecorationChanged()));

		const newDecorations: IModelDeltaDecoration[] = [];
		const newDecorationsActualIndex: number[] = [];

		for (let i = 0, len = reference.children.length; i < len; i++) {
			let oneReference = reference.children[i];
			if (this._decorationIgnoreSet.has(oneReference.id)) {
				continue;
			}
			if (oneReference.uri.toString() !== this._editor.getModel().uri.toString()) {
				continue;
			}
			newDecorations.push({
				range: oneReference.range,
				options: DecorationsManager.DecorationOptions
			});
			newDecorationsActualIndex.push(i);
		}

		const decorations = this._editor.deltaDecorations([], newDecorations);
		for (let i = 0; i < decorations.length; i++) {
			this._decorations.set(decorations[i], reference.children[newDecorationsActualIndex[i]]);
		}
	}