title: Neo4j Cypher results as JSON: Getting JsonMappingException when using JsonHelper.createJsonFrom() but only with certain queries
body: <p>I'm working on neo4vertx, a module that makes it possible to talk to a Neo4j database using Vert.x. Specifically, I'm working on feature called "query" which allows a Vert.x user
  to send a Cypher query as an eventbus message and get a JSON resultset back.</p>
  
  <p>However, I seem to run into an unexpected problem when serializing to JSON using JsonHelper.createJsonFrom() with certain queries.</p>
  
  <p>A quick example (database has stuff in it of course):</p>
  
  <pre><code>// This Fails with JsonMappingException (see below):
  String query="MATCH (n) RETURN n";
  
  // This Succeeds:
  String query="MATCH (n) RETURN n.something";
  
  //Rest of code:
  engine = new ExecutionEngine(graphDatabaseService);
  ExecutionResult result;
  result = engine.execute(query);
  
  Object object = result.iterator();
  String foo = JsonHelper.createJsonFrom(object);
  System.out.println("DEBUG (foo): " + foo);
  </code></pre>
  
  <p>Does this look familiar to anyone? We essentially want to be able to
  send any kind of query and either return an empty json string or a json
  representation not unlike the result.json that you can retrieve from the
  web interface of neo4j!</p>
  
  <h2>The Exception:</h2>
  
  <pre><code>testQuery(org.openpcf.neo4vertx.neo4j.Neo4jGraphTest)  Time elapsed: 2.362 sec  &lt;&lt;&lt; ERROR!
  org.neo4j.server.rest.domain.JsonBuildRuntimeException: org.codehaus.jackson.map.JsonMappingException: No serializer found for class org.neo4j.kernel.InternalAbstractGraphDatabase$DependencyResolverImpl and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationConfig.Feature.FAIL_ON_EMPTY_BEANS) ) (through reference chain: scala.collection.convert.MapWrapper["content"]-&gt;org.neo4j.kernel.impl.core.NodeProxy["graphDatabase"]-&gt;org.neo4j.test.["dependencyResolver"])
  
  ...
  </code></pre>