### Question:
HashShaLockedDomainPrefixGenerator implements LockedDomainPrefixGenerator { public String getLockedDomainPrefix(Uri gadgetUri) { return getLockedDomainPrefix(gadgetUri.toString().toLowerCase()); }  String getLockedDomainPrefix(Uri gadgetUri); String getLockedDomainPrefix(String token);  }### Answer:
@Test public void generate() { Uri uri = Uri.parse("http: assertEquals("e5bld32ce9pe5ln81rjhe0d0e1vao1ba", generator.getLockedDomainPrefix(uri)); }
@Test(expected = NullPointerException.class) public void isNull() { generator.getLockedDomainPrefix((Uri)null); }