src/vs/workbench/common/editor/resourceEditorInput.ts/AbstractResourceEditorInput/mediumDescription
class AbstractResourceEditorInput:	private get mediumDescription(): string {
		if (typeof this._mediumDescription !== 'string') {
			this._mediumDescription = this.labelService.getUriLabel(dirname(this._preferredResource), { relative: true });
		}

		return this._mediumDescription;
	}