Will recursive or mutually recursive bounds on TypeVar be supported?

Start with the recursive TypeVar example in example.py and review the linked typing discussion at issue 59. Compare it with the pymcts/tree.py example, then determine the expected behavior for TypedCons, IntCons, and the rejected BadCons case; done means recursive or mutually recursive bounds are either supported consistently or the limitation is clearly resolved.

Reading through the discussion at https://github.com/python/typing/issues/59, there was an example that had TypeVar bound that referenced itself. Is this intended to be eventually implemented? The actual PEP just has a bare Comparable.

A motivating example (from the Java world) is discussed here, in the context of their Enum. An example in Python:

from typing import Generic, Optional, Tuple, TypeVar  

# Would like to write bound='TypedCons[T, V]' here, where T is self-referential
T = TypeVar('T', bound='TypedCons')
V = TypeVar('V')  


class TypedCons(Generic[T, V]):  
    def __init__(self, value: V, cdr: Optional[T]=None) -> None:  
        self.value = value  
        self.cdr = cdr  

    def first_two(self) -> Tuple[T, T]:  
        # Fails without cast with "Incompatible return value type: expected Tuple[T`1, T`1], got Tuple[example.TypedCons[T`1, V`2], T`1]"  
        return self, self.cdr  

class IntCons(TypedCons['IntCons', int]):  
    pass

# Recursive bound would reject this
class BadCons(TypedCons['IntCons', str]):  
    pass  

If I try to write the recursive bound, I get:

example.py:3: error: Invalid type "example.T"

A similar example where this is needed is at https://github.com/smallnamespace/pymcts/blob/b5e1375e67983ef7b5baa2511c680074fd31b00c/pymcts/tree.py#L78 -- here we need to use the fact that N and Node are identical.