code: function updateLevel(cb){
  			conn.query("SELECT MAX(level) AS max_level FROM units WHERE unit IN(?)", [objUnit.parent_units], function(rows){
  				if (rows.length !== 1)
  					throw Error("not a single max level?");
  				conn.query("UPDATE units SET level=? WHERE unit=?", [rows[0].max_level + 1, objUnit.unit], function(){
  					cb();
  				});
  			});
  		}
docs: function updateBestParent(cb){ conn.query("UPDATE units SET best_parent_unit=? WHERE unit=?", [objValidationState.best_parent_unit, objUnit.unit], function(){ cb(); }); }