[Bug]: Test runner(Python SDK) fails when generic type is specified as a type for pardo element

[m-morozov-kw]

What happened?

Test env details:
Python 3.11.3
Beam SDK version: 2.60.0

Hello! We want to use generic types as a type annotation for elements in Pardo in Python SDK to improve code readability, but it seems like Test Runner doesn't support that. Are there any options for how we can work around that?
Please find the reproduction snippet:
Create a file like /tmp/test_pardo.py

import apache_beam as beam
from typing import TypeVar, Generic

from apache_beam.testing.util import assert_that, equal_to
from apache_beam.testing.test_pipeline import TestPipeline

T = TypeVar("T")


class ResultContainer(Generic[T]):
    def __init__(self, payload: T) -> None:
        self.payload = payload


class SomeDoFn(beam.DoFn):
    def process(self, data: ResultContainer[int]):
        yield data.payload + 1


def test_pardo():
    with TestPipeline() as p:
        output = p | beam.Create([ResultContainer(1)]) | beam.ParDo(SomeDoFn())
        assert_that(
            label="check result",
            actual=output,
            matcher=equal_to([2]),
        )

Run it as a test

pytest /tmp/test_pardo.py

Expected: test passes
Actual behavior:

    def __subclasscheck__(self, cls):
>       raise TypeError("Subscripted generics cannot be used with"
                        " class and instance checks")
E       TypeError: Subscripted generics cannot be used with class and instance checks

Thank you

Issue Priority

Priority: 2 (default / most bugs should be filed as P2)

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[m-morozov-kw]

.add-labels python

[github-actions]

Label generic type annotations cannot be managed because it does not exist in the repo. Please check your spelling.

[liferoad]

@jrmccluskey do we support this?