Fishing bobbers cannot be summoned

The bug

Fishing bobbers are entities but cannot be summoned. You can tell they are by looking in your debug screen when it is just you and a fishing bobber in the world. It will say there are two entities.

Steps to reproduce

1. /summon fishing_bobber

 You get an error: "Unknown entity: minecraft:fishing_bobber"

 

Additional Information

This might be considered a feature request but being that you can summon leash knots (for some reason) and that MC-30568 was valid this should be considered at the very least.