code: private void markVertexUpdated(AtlasVertex vertex) {
          Date   now         = new Date();
          Number currVersion = vertex.getProperty(Constants.VERSION_PROPERTY_KEY, Number.class);
          long   newVersion  = currVersion == null ? 1 : (currVersion.longValue() + 1);
  
          vertex.setProperty(Constants.MODIFICATION_TIMESTAMP_PROPERTY_KEY, now.getTime());
          vertex.setProperty(Constants.VERSION_PROPERTY_KEY, newVersion);
      }
docs: /*
  increment the version value for this vertex