use crate::extension::end_of_index_entry::SIGNATURE;use crate::extension::Signature; /// Write this extension to out and generate a hash of `hash_kind` over all `prior_extensions` which are specified as `(signature, size)`/// pair. `one_past_entries` is the offset to the first byte past the entries, which is also the first byte of the signature of the/// first extension in `prior_extensions`. Note that `prior_extensions` must have been written prior to this one, as the name suggests,/// allowing this extension to be the last one in the index file.////// Even if there are no `prior_extensions`, this extension will be written unconditionally.pub fn write_to(    mut out: impl std::io::Write,    hash_kind: git_hash::Kind,    offset_to_extensions: u32,    prior_extensions: impl IntoIterator<Item = (Signature, u32)>,) -> Result<(), std::io::Error> {    out.write_all(&SIGNATURE)?;    let extension_size: u32 = 4 + hash_kind.len_in_bytes() as u32;    out.write_all(&extension_size.to_be_bytes())?;     out.write_all(&offset_to_extensions.to_be_bytes())?;     let mut hasher = git_features::hash::hasher(hash_kind);    for (signature, size) in prior_extensions {        hasher.update(&signature);        hasher.update(&size.to_be_bytes());    }    out.write_all(&hasher.digest())?;     Ok(())}