Can anyone tell me what this plastic part is on my gas door?

I found this black plastic part broke on my gas door. What is it? This picture is from another vehicle. It clips on the hinge of the door. it doesn’t seem like it’s needed. Is it a spring of some sort?

 

Looks like it’s a small cable that holds your gas cap and keeps it from falling on the ground. I’d just remove it if it’s broken, there’s already a holder built into the door.

 

The tether keeps you from losing your gas cap. I believe the part you've circled prevents the door from opening too wide. It's probably not necessary but if you're not careful the gas door could open too far and hit the paint on the trucks body damaging it.

 

Sorry. Yea i know what the cable is for. It’s the other black plastic. Your prob right, its to keep the door from opening too much.
Thanks.

 

Part out.

 

Spring clip, makes the door “pop” open when released

 

It's the spring clip as mentioned above. However the metal part is broken. Time to order a new one.