src/vs/editor/browser/editorExtensions.ts/MultiCommand/runCommand
class MultiCommand:	public runCommand(accessor: ServicesAccessor, args: any): void | Promise<void> {
		const logService = accessor.get(ILogService);
		logService.trace(`Executing Command '${this.id}' which has ${this._implementations.length} bound.`);
		for (const impl of this._implementations) {
			const result = impl.implementation(accessor, args);
			if (result) {
				logService.trace(`Command '${this.id}' was handled by '${impl.name}'.`);
				if (typeof result === 'boolean') {
					return;
				}
				return result;
			}
		}
		logService.trace(`The Command '${this.id}' was not handled by any implementation.`);
	}