### Question:
HllUtil { public static double pow2(int p) { if (p < 0) { return 1.0 / (1L << -p); } if (p > 0) { return 1L << p; } return 1.0; }  static double pow2(int p); static long murmurHash64A(byte[] data, int seed);  }### Answer:
@Test public void testPow2() { assertThat(HllUtil.pow2(0)).isEqualTo(1.0); assertThat(HllUtil.pow2(8)).isEqualTo(256.0); assertThat(HllUtil.pow2(-8)).isEqualTo(0.00390625); }