src/vs/platform/log/common/fileLog.ts/FileLogger/error
class FileLogger:	error(): void {
		if (this.getLevel() <= LogLevel.Error) {
			const arg = arguments[0];

			if (arg instanceof Error) {
				const array = Array.prototype.slice.call(arguments) as any[];
				array[0] = arg.stack;
				this._log(LogLevel.Error, this.format(array));
			} else {
				this._log(LogLevel.Error, this.format(arguments));
			}
		}
	}