fn set_default_toplevel_value<'ob>(
symbol: Symbol<'_>,
value: Gc<ObjectType<'_>>,
env: &'ob mut Rt<Env<'_>>,
) -> Result<Gc<ObjectType<'ob>>>
fn set_default_toplevel_value<'ob>(
symbol: Symbol<'_>,
value: Gc<ObjectType<'_>>,
env: &'ob mut Rt<Env<'_>>,
) -> Result<Gc<ObjectType<'ob>>>