Sums { public static ReduceByKey.CombineFunctionWithIdentity<Float> ofFloats() { return SUMS_OF_FLOAT; } private  Sums(); static ReduceByKey.CombineFunctionWithIdentity<Long> ofLongs(); static ReduceByKey.CombineFunctionWithIdentity<Integer> ofInts(); static ReduceByKey.CombineFunctionWithIdentity<Float> ofFloats(); static ReduceByKey.CombineFunctionWithIdentity<Double> ofDoubles();  }
@Test public void testSumOfFloats() { assertEquals(6f, (float) apply(Stream.of(1f, 2f, 3f), Sums.ofFloats()), 0.001); }