### Question:
HllV5 { public HllV5 pfMerge(HllV5... others) { if (others.length < 1) { return this; } HllhdrV5[] otherHlls = new HllhdrV5[others.length]; for (int i = 0; i < others.length; i++) { otherHlls[i] = others[i].hllhdr; } hllhdr.hllMerge(otherHlls); hllhdr.invalidateCache(); return this; } HllV5(byte[] representation);   HllV5(); long pfCount(); boolean pfAdd(byte[] element); HllV5 pfMerge(HllV5... others); byte[] dumpRepr(); static HllV5Builder newBuilder();  }### Answer:
@Test public void testPfMerge() throws Exception { HllV5 hll = HllV5.newBuilder().build(); HllV5 other = HllV5.newBuilder() .withRepr(TestUtil.getResourceAsBytes("v5/dense_cached_99571.dat")) .build(); assertThat(hll.pfMerge(other).pfCount()).isEqualTo(99571L); }