pub trait Sealed {} impl Sealed for git_ref::Reference {} /// Extensions for [revision specifications][git_revision::Spec].pub trait RevSpecExt {    /// Attach [`Repository`][crate::Repository] to the given rev-spec.    fn attach(self, repo: &crate::Repository) -> crate::revision::Spec<'_>;} impl RevSpecExt for git_revision::Spec {    fn attach(self, repo: &crate::Repository) -> crate::revision::Spec<'_> {        crate::revision::Spec {            inner: self,            first_ref: None,            second_ref: None,            repo,        }    }}