src/vs/workbench/services/extensions/common/abstractExtensionService.ts/AbstractExtensionService/createLogger
class AbstractExtensionService:	protected createLogger(): Logger {
		return new Logger((severity, source, message) => {
			if (this._isDev && source) {
				this._logOrShowMessage(severity, `[${source}]: ${message}`);
			} else {
				this._logOrShowMessage(severity, message);
			}
		});
	}