anchor.diff:  
   It is strongly recommended to update off-heap memory of values directly only within a context, and update or write lock held. Within a context, you are provided with an entry object of `MapEntry` type. To re-compute entry checksum manually, cast that object to `ChecksumEntry` type and call the `.updateChecksum()` method:
   
  -``` java
  +```java
   try (ChronicleMap<Integer, LongValue> map = ChronicleMap
           .of(Integer.class, LongValue.class)
           .entries(1)
  
positive.code: Unlike `ConcurrentHashMap`, `ChronicleMap` stores its data off-heap; often in a memory mapped file.
  It is recommended that you call `close()` when you have finished working with a `ChronicleMap`.
  
  ``` java
  map.close()
  ```
  
  
negative.code:  PostalCodeRange range = cachedPostalCodeRange.get();
   cityPostalCodes.getUsing(city, range);
   // process the range...
  ```
  
   - If the value type implements `BytesMarshallable`, or `Externalizable`, then `ChronicleMap` attempts to
   reuse the given `using` object by deserializing the value into the given object.
  