src/vs/editor/contrib/inlayHints/browser/inlayHintsController.ts/InlayHintsController/_removeAllDecorations
class InlayHintsController:	private _removeAllDecorations(): void {
		this._editor.deltaDecorations(Array.from(this._decorationsMetadata.keys()), []);
		for (let obj of this._decorationsMetadata.values()) {
			obj.classNameRef.dispose();
		}
		this._decorationsMetadata.clear();
	}