### Question:
ContainerDBServiceProviderImpl implements ContainerDBServiceProvider { @Override public void storeContainerKeyMapping(ContainerKeyPrefix containerKeyPrefix, Integer count) throws IOException { containerKeyTable.put(containerKeyPrefix, count); } @Inject  ContainerDBServiceProviderImpl(DBStore dbStore,
                                        Configuration sqlConfiguration); @Override void close(); @Override void initNewContainerDB(Map<ContainerKeyPrefix, Integer>
                                     containerKeyPrefixCounts); @Override void storeContainerKeyMapping(ContainerKeyPrefix containerKeyPrefix,
                                       Integer count); @Override void storeContainerKeyCount(Long containerID, Long count); @Override long getKeyCountForContainer(Long containerID); @Override boolean doesContainerExists(Long containerID); @Override Integer getCountForContainerKeyPrefix(
      ContainerKeyPrefix containerKeyPrefix); @Override Map<ContainerKeyPrefix, Integer> getKeyPrefixesForContainer(
      long containerId); @Override Map<ContainerKeyPrefix, Integer> getKeyPrefixesForContainer(
      long containerId, String prevKeyPrefix); @Override Map<Long, ContainerMetadata> getContainers(int limit,
                                                    long prevContainer); @Override void deleteContainerMapping(ContainerKeyPrefix containerKeyPrefix); @Override long getCountForContainers(); @Override TableIterator getContainerTableIterator(); @Override void storeContainerCount(Long count); @Override void incrementContainerCountBy(long count);  }### Answer:
@Test public void testStoreContainerKeyMapping() throws Exception { long containerId = System.currentTimeMillis(); Map<String, Integer> prefixCounts = new HashMap<>(); prefixCounts.put(keyPrefix1, 1); prefixCounts.put(keyPrefix2, 2); prefixCounts.put(keyPrefix3, 3); for (String prefix : prefixCounts.keySet()) { ContainerKeyPrefix containerKeyPrefix = new ContainerKeyPrefix( containerId, prefix, 0); containerDbServiceProvider.storeContainerKeyMapping( containerKeyPrefix, prefixCounts.get(prefix)); } Assert.assertEquals(1, containerDbServiceProvider.getCountForContainerKeyPrefix( new ContainerKeyPrefix(containerId, keyPrefix1, 0)).longValue()); Assert.assertEquals(2, containerDbServiceProvider.getCountForContainerKeyPrefix( new ContainerKeyPrefix(containerId, keyPrefix2, 0)).longValue()); Assert.assertEquals(3, containerDbServiceProvider.getCountForContainerKeyPrefix( new ContainerKeyPrefix(containerId, keyPrefix3, 0)).longValue()); }