Is this is a valid use of ParamSpec?

[RobertCraigie]

from typing_extensions import ParamSpec
from typing import Dict, Generic, Optional

P = ParamSpec('P')

class HTTP:
    def __init__(self, headers: Optional[Dict[str, str]] = None) -> None:
        ...

class _Base(Generic[P]):
    def __init__(self, foo: str, *args: P.args, **kwargs: P.kwargs) -> None:
        ...

Base = _Base[HTTP]

class Sub(Base):
    def __init__(self) -> None:
        super().__init__(foo='foo', headers={'foo': 'bar'})

Pyright complains:

foo.py:23:37 - error: No parameter named "headers" (reportGeneralTypeIssues)
foo.py:23:9 - error: Argument missing for parameter "__p0" (reportGeneralTypeIssues)

[RobertCraigie]

Found out that it is not: #2667