/// following are true:
///
/// * If a protocol name is an empty string, e.g. `"Cons=1,3 =3-5"`.
- /// * If a protocol name cannot be parsed as utf-8.
- /// * If the version numbers are an empty string, e.g. `"Cons="`.
+ /// * If an entry has no equals sign, e.g. `"Cons=1,3 Desc"`.
+ /// * If there is leading or trailing whitespace, e.g. `" Cons=1,3 Link=3"`.
+ /// * If there is any other extra whitespice, e.g. `"Cons=1,3 Link=3"`.
fn parse_protocol_and_version_str<'a>(
protocol_string: &'a str,
) -> Result<Vec<(&'a str, &'a str)>, ProtoverError> {