Function enum_str_value 

pub(crate) fn enum_str_value<'a>(
    result: Result<Cow<'static, str>, PlanError>,
) -> Value<'a>

Converts an ValueEnum::as_enum_str result into a Value. Shared by the blanket From<&T> impl below and by callers that only have an owned enum value (and so can’t borrow it for the lifetime Value<'a> requires).