code: private StatementResult employ( final Transaction tx, final String person, final String company )
      {
          return tx.run( "MATCH (person:Person {name: $person_name}) " +
                          "MATCH (company:Company {name: $company_name}) " +
                          "CREATE (person)-[:WORKS_FOR]->(company)",
                  parameters( "person_name", person, "company_name", company ) );
      }
docs: This relies on the person first having been created.