mod v1 {    fn capabilities(input: &str) -> git_transport::client::Capabilities {        git_transport::client::Capabilities::from_bytes(format!("\0{}", input).as_bytes())            .expect("valid input capabilities")            .0    }     const GITHUB_CAPABILITIES: &str = "multi_ack thin-pack side-band ofs-delta shallow deepen-since deepen-not deepen-relative no-progress include-tag allow-tip-sha1-in-want allow-reachable-sha1-in-want no-done symref=HEAD:refs/heads/main filter agent=git/github-gdf51a71f0236";    mod fetch {        mod default_features {            use crate::command::tests::v1::{capabilities, GITHUB_CAPABILITIES};            use crate::Command;             #[test]            fn it_chooses_the_best_multi_ack_and_sideband() {                assert_eq!(                    Command::Fetch.default_features(                        git_transport::Protocol::V1,                        &capabilities("multi_ack side-band side-band-64k multi_ack_detailed")                    ),                    &[("side-band-64k", None), ("multi_ack_detailed", None),]                );            }             #[test]            fn it_chooses_all_supported_non_stacking_capabilities_and_leaves_no_progress() {                assert_eq!(                    Command::Fetch.default_features(git_transport::Protocol::V1, &capabilities(GITHUB_CAPABILITIES)),                    &[                        ("multi_ack", None),                        ("thin-pack", None),                        ("side-band", None),                        ("ofs-delta", None),                        ("shallow", None),                        ("deepen-since", None),                        ("deepen-not", None),                        ("deepen-relative", None),                        ("allow-tip-sha1-in-want", None),                        ("allow-reachable-sha1-in-want", None),                        ("no-done", None),                        ("filter", None),                    ],                    "we don't enforce include-tag or no-progress"                );            }        }    }} mod v2 {    use git_transport::client::Capabilities;     fn capabilities(command: &str, input: &str) -> Capabilities {        Capabilities::from_lines(Some(Ok("version 2".into())), format!("{}={}", command, input))            .expect("valid input for V2 capabilities")    }     mod fetch {        mod default_features {            use crate::command::tests::v2::capabilities;            use crate::Command;             #[test]            fn all_features() {                assert_eq!(                    Command::Fetch.default_features(                        git_transport::Protocol::V2,                        &capabilities("fetch", "shallow filter ref-in-want sideband-all packfile-uris")                    ),                    ["shallow", "filter", "ref-in-want", "sideband-all", "packfile-uris"]                        .iter()                        .map(|s| (*s, None))                        .collect::<Vec<_>>()                )            }        }         mod initial_arguments {            use bstr::ByteSlice;             use crate::command::tests::v2::capabilities;            use crate::Command;             #[test]            fn for_all_features() {                assert_eq!(                    Command::Fetch.initial_arguments(&Command::Fetch.default_features(                        git_transport::Protocol::V2,                        &capabilities("fetch", "shallow filter sideband-all packfile-uris")                    )),                    ["thin-pack", "include-tag", "ofs-delta", "sideband-all", "packfile-uris"]                        .iter()                        .map(|s| s.as_bytes().as_bstr().to_owned())                        .collect::<Vec<_>>()                )            }        }    }     mod ls_refs {        mod default_features {            use crate::command::tests::v2::capabilities;            use crate::Command;             #[test]            fn default_as_there_are_no_features() {                assert_eq!(                    Command::LsRefs.default_features(                        git_transport::Protocol::V2,                        &capabilities("something-else", "does not matter as there are none")                    ),                    &[]                );            }        }         mod validate {            use bstr::ByteSlice;             use crate::command::tests::v2::capabilities;            use crate::Command;             #[test]            fn ref_prefixes_can_always_be_used() {                Command::LsRefs.validate_argument_prefixes_or_panic(                    git_transport::Protocol::V2,                    &capabilities("something else", "do-not-matter"),                    &[b"ref-prefix hello/".as_bstr().into()],                    &[],                );            }             #[test]            #[should_panic]            fn unknown_argument() {                Command::LsRefs.validate_argument_prefixes_or_panic(                    git_transport::Protocol::V2,                    &capabilities("other", "do-not-matter"),                    &[b"definitely-nothing-we-know".as_bstr().into()],                    &[],                );            }             #[test]            #[should_panic]            fn unknown_feature() {                Command::LsRefs.validate_argument_prefixes_or_panic(                    git_transport::Protocol::V2,                    &capabilities("other", "do-not-matter"),                    &[],                    &[("some-feature-that-does-not-exist", None)],                );            }        }    }}