### Question:
NoneDatabaseShardingAlgorithm implements SingleKeyDatabaseShardingAlgorithm<String>, MultipleKeysDatabaseShardingAlgorithm { @Override public String doEqualSharding(final Collection<String> availableTargetNames, final ShardingValue<String> shardingValue) { return availableTargetNames.isEmpty() ? null : availableTargetNames.iterator().next(); }  @Override Collection<String> doSharding(final Collection<String> availableTargetNames, final Collection<ShardingValue<?>> shardingValues); @Override String doEqualSharding(final Collection<String> availableTargetNames, final ShardingValue<String> shardingValue); @Override Collection<String> doInSharding(final Collection<String> availableTargetNames, final ShardingValue<String> shardingValue); @Override Collection<String> doBetweenSharding(final Collection<String> availableTargetNames, final ShardingValue<String> shardingValue);  }### Answer:
@Test public void assertDoEqualShardingForTargetsEmpty() { assertNull(noneDatabaseShardingAlgorithm.doEqualSharding(Collections.<String>emptyList(), null)); }
@Test public void assertDoEqualSharding() { assertThat(noneDatabaseShardingAlgorithm.doEqualSharding(targets, null), is("ds")); }