title: Deleting nodes also deletes relationships when using spring-data-neo4j, which is different from the cypher default
body: <p>I'm writing a spring-data-neo4j app, and playing around with CRUD.</p>
  
  <p>In cypher, if I am not able to delete a node that has a relationship with another node, without first deleting the relationship.</p>
  
  <p>In spring-data-neo4j that doesn't appear to have the same behaviour. When I delete a node, it also appears to delete the associated relationships too.</p>
  
  <p>Is there a way to prevent this behaviour from the default repository? How can I get spring-data to throw an exception given a deletion for a node with a relationship?</p>
  
  <p>This is the behaviour I would expect (and desire):</p>
  
  <pre><code>@NodeEntity
  class Junction {
      @GraphId Long id
  }
  
  @NodeEntity
  class Route {
      @GraphId Long id
      @Fetch Junction from
      @Fetch Junction to
  }
  
  @Transactional
  def "should not be able to delete a junction that is used"() {
      given: "a junction that is in use"
      Junction j = new Junction()
      Route r = new Route(from: j, to: new Junction())
      routeRepository.save(r)
  
      when: "the junction is removed"
      junctionRepository.delete(j)
  
      then:
      thrown SomeExceptionBecauseTheNodeHasAnAssociatedRelationship
  }
  </code></pre>