Clarification needed: What is @strawberry.federation.type(extend=True, ...) for?

[magicmark]

https://strawberry.rocks/api-reference/strawberry.type#:~:text=Whether%20the%20class%20is%20extending%20an%20existing%20type.

What does it mean to "extend" a type?

For defining an Entity, the docs gives this example:

@strawberry.federation.type(keys=["id"])
class Book:
    id: strawberry.ID
    title: str

~ source

And for Value Types,

@strawberry.type(directives=[Shareable()])
class CommonType:
    foo: str
    woops: bool = strawberry.field(directives=[Inaccessible()])

~ source

Where/what use case is extend=True for?

Is this just for federation v1 and now deprecated in v2? I do see a reference to it here: https://strawberry.rocks/docs/guides/federation-v1#reviews-service

(If this is the case, should I send a PR to clarify this in the docs somewhere? thanks!)

Thanks!

[patrick91]

@magicmark yes, that's something for federation 1 only if I remember correctly. Maybe we should remove it entirely?