code: public void createIndex(String label, String propertyName) {
          Objects.requireNonNull(label, "label cannot be null");
          Objects.requireNonNull(propertyName, "propertyName cannot be null");
          // get current session
          Neo4JSession session = currentSession();
          // transaction should be ready for io operations
          transaction.readWrite();
          // execute statement
          session.executeStatement(new Statement("CREATE INDEX ON :`" + label + "`(" + propertyName + ")"));
      }
docs: Creates an index in the neo4j database.
  
  @param label        The label associated with the Index.
  @param propertyName The property name associated with the Index.