Right now mypy throws a bunch of errors in this particular code block -

saying -

error: Subclass of "VectorProtocol", "Momentum", and "Vector2D" cannot exist: would have inconsistent method resolution order  [unreachable]

These errors have been suppressed using the type: ignore[unreachable] comments, but this should be fixed. The type: ignore[unreachable] comments should be removed from Vector (these are the only type: ignore[unreachable] comments left in the codebase).

Guessing it is not understanding that Type[VectorProtocol] can (sometimes) pass a subclass of Momentum check? Might be worth updating that. But not in this PR, these are (all) fine for now.

Originally posted by @henryiii in #219 (comment)