Neo4j record size of nodes


I would like to know what the exact size of a single node record in the 'nodestore.db' is. The book, Graph Databases by Ian Robinson, says a single node record has a fixed size of 9 bytes (1xinUse;4xRelation;4xPropertie) . However, various sources [1] seem to imply there is an additional 'label flag' with 5 bytes and an additional 'extra' flag of one byte, which would result in a record size of 15 bytes. Are there any differences regarding the version of Neo4j being used, unfortunately I could not find anything in the documentation.

Thanks in advance,

[1] Understanding Neo4j’s data on disk - Knowledge Base