src/vs/workbench/contrib/terminal/browser/terminalDecorationsProvider.ts/TerminalDecorationsProvider/provideDecorations
class TerminalDecorationsProvider:	provideDecorations(resource: URI): IDecorationData | undefined {
		if (resource.scheme !== Schemas.vscodeTerminal) {
			return undefined;
		}

		const instance = this._terminalService.getInstanceFromResource(resource);
		if (!instance) {
			return undefined;
		}

		const primaryStatus = instance?.statusList?.primary;
		if (!primaryStatus?.icon) {
			return undefined;
		}

		return {
			color: getColorForSeverity(primaryStatus.severity),
			letter: primaryStatus.icon,
			tooltip: primaryStatus.tooltip
		};
	}