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

		return this._mediumTitle;
	}