use std::path::Path; use gix_error::{ErrorExt, OptionExt, ValidationError}; use crate::Bundle; /// Initializationimpl Bundle {    /// Create a `Bundle` from `path`, which is either a pack file _(*.pack)_ or an index file _(*.idx)_.    ///    /// The corresponding complementary file is expected to be present.    ///    /// The `object_hash` is a way to read (and write) the same file format with different hashes, as the hash kind    /// isn't stored within the file format itself.    pub fn at(path: impl AsRef<Path>, object_hash: gix_hash::Kind) -> Result<Self, gix_error::Exn> {        Self::at_inner(path.as_ref(), object_hash)    }     fn at_inner(path: &Path, object_hash: gix_hash::Kind) -> Result<Self, gix_error::Exn> {        let ext = path            .extension()            .and_then(std::ffi::OsStr::to_str)            .ok_or_raise_erased(|| {                ValidationError::new(format!(                    "An 'idx' extension is expected of an index file: '{}'",                    path.display()                ))            })?;        Ok(match ext {            "idx" => Self {                index: crate::index::File::at(path, object_hash)?,                pack: crate::data::File::at(path.with_extension("pack"), object_hash)?,            },            "pack" => Self {                pack: crate::data::File::at(path, object_hash)?,                index: crate::index::File::at(path.with_extension("idx"), object_hash)?,            },            _ => {                return Err(ValidationError::new(format!(                    "An 'idx' extension is expected of an index file: '{}'",                    path.display()                ))                .raise_erased());            }        })    }}