Function assumed_version 

pub fn assumed_version(
    header: Option<&str>,
    signal: Option<ProtocolVersion>,
) -> ProtocolVersion

The version a request is assumed to be, given whatever signals it carries.

signal is the session’s negotiated version, or the _meta version on a stateless request. header is the HTTP header. The session wins: a header that disagreed with the session would already have been rejected by check_protocol_header, and a session is a stronger statement of intent than a header.

With neither, the request is assumed to be assumed_version_without_signal.

Examples

use protocol_droid::domain::{ProtocolVersion, assumed_version};

// Nothing to go on at all.
assert_eq!(assumed_version(None, None), ProtocolVersion::V2025_03_26);
// A header beats the fallback.
assert_eq!(
    assumed_version(Some("2025-11-25"), None),
    ProtocolVersion::V2025_11_25,
);