Function fips_codes::counties_by_state_fips_id

pub fn counties_by_state_fips_id(
    state_id: u8
) -> Option<impl Iterator<Item = (u16, &'static str)>>

use std::collections::HashMap;
use fips_codes::counties_by_state_fips_id;
let counties = counties_by_state_fips_id(46).unwrap();
let map = counties.collect::<HashMap<_, _>>();
assert_eq!(map.get(&0), Some(&"South Dakota"));
assert_eq!(map.get(&2), None);
assert_eq!(map.get(&7), Some(&"Bennett County"));