Function route_hashmap_path 

pub fn route_hashmap_path<'a, 'k, I>(
    name: &'a str,
    my_prefix: &str,
    field_name: &str,
    inner_prefix: &str,
    keys: I,
) -> Option<(&'a str, String)>
where
    I: IntoIterator<Item = &'k str>,