/// A way to indicate if a lookup, despite successful, was ambiguous or yielded exactly/// one result in the particular index.// TODO: find better name, ambiguous with git_pack::index::PrefixLookupResult (entry_index inside)pub type PrefixLookupResult = Result<git_hash::ObjectId, ()>; /// A potentially ambiguous prefix for use with `Handle::disambiguate_prefix()`.#[derive(Debug, Copy, Clone)]pub struct PotentialPrefix {    id: git_hash::ObjectId,    hex_len: usize,} impl PotentialPrefix {    /// Create a new potentially ambiguous prefix from an `id` and the desired minimal `hex_len`.    ///    /// It is considered ambiguous until it's disambiguated by validating that there is only a single object    /// matching this prefix.    pub fn new(id: impl Into<git_hash::ObjectId>, hex_len: usize) -> Result<Self, git_hash::prefix::Error> {        let id = id.into();        git_hash::Prefix::new(&id, hex_len)?;        Ok(PotentialPrefix { id, hex_len })    }     /// Transform ourselves into a `Prefix` with our current hex lengths.    pub fn to_prefix(&self) -> git_hash::Prefix {        git_hash::Prefix::new(self.id, self.hex_len).expect("our hex-len to always be in bounds")    }     pub(crate) fn inc_hex_len(&mut self) {        self.hex_len += 1;        assert!(self.hex_len <= self.id.kind().len_in_hex());    }     pub(crate) fn id(&self) -> &git_hash::oid {        &self.id    }     pub(crate) fn hex_len(&self) -> usize {        self.hex_len    }} ///pub mod existing {    use git_hash::ObjectId;     /// The error returned by the [`find(…)`][crate::FindExt::find()] trait methods.    #[derive(Debug, thiserror::Error)]    #[allow(missing_docs)]    pub enum Error<T: std::error::Error + 'static> {        #[error(transparent)]        Find(T),        #[error("An object with id {} could not be found", .oid)]        NotFound { oid: ObjectId },    }} ///pub mod existing_object {    use git_hash::ObjectId;     /// The error returned by the various [`find_*()`][crate::FindExt::find_commit()] trait methods.    #[derive(Debug, thiserror::Error)]    #[allow(missing_docs)]    pub enum Error<T: std::error::Error + 'static> {        #[error(transparent)]        Find(T),        #[error(transparent)]        Decode(git_object::decode::Error),        #[error("An object with id {oid} could not be found")]        NotFound { oid: ObjectId },        #[error("Expected object of kind {expected}")]        ObjectKind { expected: git_object::Kind },    }} ///pub mod existing_iter {    use git_hash::ObjectId;     /// The error returned by the various [`find_*_iter()`][crate::FindExt::find_commit_iter()] trait methods.    #[derive(Debug, thiserror::Error)]    #[allow(missing_docs)]    pub enum Error<T: std::error::Error + 'static> {        #[error(transparent)]        Find(T),        #[error("An object with id {oid} could not be found")]        NotFound { oid: ObjectId },        #[error("Expected object of kind {expected}")]        ObjectKind { expected: git_object::Kind },    }}