### Question:
SessionContainer implements ISessionContainer { public SessionContainer(final String hostName) { this.hostName = hostName; } SessionContainer(final String hostName); String getHostName(); String getSessionToken(String collectionLink); String resolveGlobalSessionToken(RxDocumentServiceRequest request); @Override ISessionToken resolvePartitionLocalSessionToken(RxDocumentServiceRequest request, String partitionKeyRangeId); @Override void clearTokenByCollectionFullName(String collectionFullName); @Override void clearTokenByResourceId(String resourceId); @Override void setSessionToken(RxDocumentServiceRequest request, Map<String, String> responseHeaders); @Override void setSessionToken(String collectionRid, String collectionFullName, Map<String, String> responseHeaders);  }### Answer:
@Test(groups = "unit") public void sessionContainer() throws Exception { SessionContainer sessionContainer = new SessionContainer("127.0.0.1"); int numCollections = 2; int numPartitionKeyRangeIds = 5; for (int i = 0; i < numCollections; i++) { String collectionResourceId = ResourceId.newDocumentCollectionId(getRandomDbId(), getRandomCollectionId() + i).getDocumentCollectionId().toString(); String collectionFullName = "dbs/db1/colls/collName_" + i; for (int j = 0; j < numPartitionKeyRangeIds; j++) { String partitionKeyRangeId = "range_" + j; String lsn = "1#" + j + "#4=90#5=2"; sessionContainer.setSessionToken( collectionResourceId, collectionFullName, ImmutableMap.of(HttpConstants.HttpHeaders.SESSION_TOKEN, partitionKeyRangeId + ":" + lsn)); } } RxDocumentServiceRequest request = RxDocumentServiceRequest.create(OperationType.ReadFeed, ResourceType.DocumentCollection, "dbs/db1/colls/collName_1", IOUtils.toInputStream("content1", "UTF-8"), new HashMap<>()); ISessionToken sessionToken = sessionContainer.resolvePartitionLocalSessionToken(request, "range_1"); assertThat(sessionToken.getLSN()).isEqualTo(1); DocumentServiceRequestContext dsrContext = new DocumentServiceRequestContext(); PartitionKeyRange resolvedPKRange = new PartitionKeyRange(); resolvedPKRange.setId("range_" + (numPartitionKeyRangeIds + 10)); GatewayTestUtils.setParent(resolvedPKRange, ImmutableList.of("range_2", "range_x")); dsrContext.resolvedPartitionKeyRange = resolvedPKRange; request.requestContext = dsrContext; sessionToken = sessionContainer.resolvePartitionLocalSessionToken(request, resolvedPKRange.getId()); assertThat(sessionToken.getLSN()).isEqualTo(2); }