seqMap.js

//@flow
declare var test: any
declare var expect: any
import {Seq} from "immutable"
test("hmmm", () => {


    const xs : Seq<number, string> = Seq.of("a", "b", "c")

  // this does not typecheck, map not found in Seq
    const ys :  Seq<number, string> = xs.map(x => x + x)

  // map is in fact in seq, the following assertion passes
    expect(ys.toJS()).toEqual(["aa", "bb", "cc"])
})