from typing import Callable

class Connection:
    def __init__(self, host: str) -> None:
        self.host = host

    def clone(self) -> "Connection":
        return Connection(self.host)


def get_connection() -> Connection | None:
    return Connection("localhost")


def make_query_func() -> Callable[[], str]:
    conn = get_connection()
    assert conn is not None, "connection required"
    # Reassign after assert narrowing
    conn = conn.clone()

    def query() -> str:
        # FP: `Connection | None` is not assignable to `Connection`
        current: Connection = conn  # E: bad-assignment
        return f"querying {current.host}"

    return query