public Item withPrimaryKey(String hashKeyName, Object hashKeyValue,
            String rangeKeyName, Object rangeKeyValue) {
        return withKeyComponent(hashKeyName, hashKeyValue)
              .withKeyComponent(rangeKeyName, rangeKeyValue);
    }
Convenient method to set the attributes of this item from the given
hash and range primary key.
aws-java-sdk-dynamodb/src/main/java/com/amazonaws/services/dynamodbv2/document/Item.java