### Question:
Hashing { public static byte[] SHA1(byte[] bytes) { requireNonNull(bytes, "bytes is null"); MessageDigest md = getSHA1MessageDigest(); return md.digest(bytes); }  static int hashcode(Object o); static int identityHash(int h); static int juHashMapHash(int h); static int wangJenkinsHash(int h); static final int murmur3BaseStep(int h); static byte[] SHA1(byte[] bytes); static byte[] SHA256(byte[] bytes);  }### Answer:
@Test public void sha1() throws Exception { assertArrayEquals(MessageDigest.getInstance("SHA-1").digest(A), Hashing.SHA1(A)); assertArrayEquals(MessageDigest.getInstance("SHA-1").digest(B), Hashing.SHA1(B)); }
@Test(expected = NullPointerException.class) public void sha1NPE() { Hashing.SHA1(null); }