Why not `TypeVarTuple`?

TypeVarTuple is about to be introduced in Python 3.11, but it's already usable with typing_extensions.

Docs: https://docs.python.org/3.11/library/typing.html#typing.TypeVarTuple

Example:

from typing import Generic, Literal, TypeVar
from typing_extensions import TypeVarTuple, Unpack

dims = TypeVarTuple("dims")
dtype = TypeVar("dtype")
dim1 = Literal["dim1"]
dim2 = Literal["dim2"]
dim3 = Literal["dim3"]
batch = Literal["batch"]
c1 = Literal["c1"]
c2 = Literal["c2"]

class f32(Generic[Unpack[dims]]): ...
class PyTree(Generic[dtype]): ...

def matrix_multiply(x: f32[dim1, dim2], y: f32[dim2, dim3]) -> f32[dim1, dim3]:
    ...

def accepts_pytree_of_ints(x: PyTree[int]):
    ...

def accepts_pytree_of_arrays(x: PyTree[f32[batch, None, c2]]):
    ...

The issue names no repository files or tests. Start by reviewing the project's current typing support against Python 3.11's TypeVarTuple documentation and the typing_extensions examples; done would require a decided scope and support for the examples shown.