/**
  * Returns a new ClassQuery object.
  *
  * @param     string $modelAlias The alias of a model in the query
  * @param     Criteria $criteria Optional Criteria to build the query from
  *
  * @return    ClassQuery
  */
 public static function create($modelAlias = null, $criteria = null)
 {
     if ($criteria instanceof ClassQuery) {
         return $criteria;
     }
     $query = new ClassQuery();
     if (null !== $modelAlias) {
         $query->setModelAlias($modelAlias);
     }
     if ($criteria instanceof Criteria) {
         $query->mergeWith($criteria);
     }
     return $query;
 }