Method upcast

crates/vm/src/object/core.rs:2244–2254

(self)

    }
    #[inline]
    pub fn upcast<U: PyPayload + StaticType>(self) -> PyRef<U>
    where
        T: StaticType,
    {
        debug_assert!(T::static_type().is_subtype(U::static_type()));
        let obj: PyObjectRef = self.into();
        match obj.downcast::<U>() {
            Ok(upcast_ref) => upcast_ref,
            Err(_) => unsafe { core::hint::unreachable_unchecked() },
        }
    }
}

impl<T: crate::class::PySubclass> Py<T> {