GH-2246 - Deterministic mapping of records with mixed results.

If a record contains more than just a node, for example
a node and an additional field, the labels were ignored.
The default behaviour was to take the nodes provided by the
node description to instantiate the entity class.
This can lead to problems with abstract base classes, because
the detailed information which concrete implementation to choose
from was more or less random.

Closes #2246

Author: meistermeier

src/main/java/org/springframework/data/neo4j/core/mapping/DefaultNeo4jEntityConverter.java

@@ -220,6 +220,7 @@ private static MapAccessor mergeRootNodeWithRecord(Node node, MapAccessor record
 		Map<String, Object> mergedAttributes = new HashMap<>(node.size() + record.size() + 1);
 
 		mergedAttributes.put(Constants.NAME_OF_INTERNAL_ID, node.id());
+		mergedAttributes.put(Constants.NAME_OF_LABELS, node.labels());
 		mergedAttributes.putAll(node.asMap(Function.identity()));
 		mergedAttributes.putAll(record.asMap(Function.identity()));