### Question:
PrefixKeyHashingScheme implements KeyHashingScheme { @Override public String hash(final String storageKey) { return prefix + backingScheme.hash(storageKey); } PrefixKeyHashingScheme(final String prefix, final KeyHashingScheme backingScheme); @Override String hash(final String storageKey);  }### Answer:
@Test public void addsPrefixToBackingScheme() { assertEquals("prefixhash", impl.hash(KEY)); }