ListenableFuture<?>[] futures = new ListenableFuture<?>[0];
    Callable<String> combiner =
        new Callable<String>() {
          @Override
          public String call() throws Exception {
            return "hi";
          }
        };

    // We'd like for all the following to compile.
    ListenableFuture<String> unused;

    // Compiles:

const h = "foo" > "bar"    // h == true  (untyped boolean constant)
const j = true             // j == true  (untyped boolean constant)
const k = 'w' + 1          // k == 'x'   (untyped rune constant)
const l = "hi"             // l == "hi"  (untyped string constant)
const m = string(k)        // m == "x"   (type string)
const Σ = 1 - 0.707i       //            (untyped complex constant)

    ListenableFuture<?>[] futures = new ListenableFuture<?>[0];
    Callable<String> combiner =
        new Callable<String>() {
          @Override
          public String call() throws Exception {
            return "hi";
          }
        };

    // We'd like for all the following to compile.
    ListenableFuture<String> unused;

    // Compiles: