text: /* @flow */
  
  import type { Name } from "./name";
  import type { Grade } from "./grade";
  import type { Distance } from "./distance";
  
  import name from "./name";
  import grade from "./grade";
  import distance from "./distance";
  
  export { name, distance, grade };
  
  export type Fields = {
    name: Name,
    distance: Distance,
    grade: Grade,
  };
  
  type Spec = {
    name: Name,
    distance: Distance,
    grade: Grade,
  };
  
  export default function fields (spec: Spec): Fields {
    return Object.freeze(spec);
  }
  