Method __instancecheck__

crates/vm/src/builtins/union.rs:131–145

(
        zelf: PyRef<Self>,
        obj: PyObjectRef,
        vm: &VirtualMachine,
    )

    #[pymethod]
    fn __instancecheck__(
        zelf: PyRef<Self>,
        obj: PyObjectRef,
        vm: &VirtualMachine,
    ) -> PyResult<bool> {
        if zelf
            .args
            .iter()
            .any(|x| x.class().is(vm.ctx.types.generic_alias_type))
        {
            Err(vm.new_type_error("isinstance() argument 2 cannot be a parameterized generic"))
        } else {
            obj.is_instance(zelf.__args__().as_object(), vm)
        }
    }

    #[pymethod]
    fn __subclasscheck__(