Unit testing works on the smallest testable parts of the code that deal with few inputs and a single output. When you modify Neo4j data stores using Java code, especially in embedded applications, you make use of the ImpermanentGraphDatabase file together with Neo4j APIs to test the code. The APIs you can use include the Java API, is the Neo4j traversal framework, and Cypher. The REST API does not much use with Java code. As an alternative, you can use GraphUnit to perform the integration testing. We will take a look at both scenarios in the following sections. For the purpose of testing, let's take an example graph that initially creates two nodes and a relationship to connect them and sets properties on the nodes and the relationship. The assertions that a unit test would apply on this graph and its functionality would be: