Subject

when attempting to subclassurllib3.Retry -- one would want to implementdef increment(...) -> Self: as bothincrement andnewpreserve the type but label the return value asRetry (essentially breaking subclassing types):

if the codebase were python 3.11+ I would usefrom typing import Self -- it appears elsewhere in the codebase one-offSelfTTypeVars are created -- that pattern could be followed here

alternatively theTYPE_CHECKING trick could be used and is understood by the current major type checkers:

if TYPE_CHECKING:    from typing_extensions import Self

Environment

N/A -- latest primary branch source, mypy 1.9

Steps to Reproduce

fromtypingimportAny,Selfimporturllib3classMyRetry(urllib3.Retry):defincrement(self,*a:Any,**k:Any)->Self:# type error on this line!returnsuper().increment(*a,**k)

$mypy t.pyt.py:5: error: Incompatible return value type (got "Retry", expected "Self")  [return-value]Found 1 error in 1 file (checked 1 source file)

Expected Behavior

no errors

Actual Behavior

shown above