private static void addMapping(String className, JPQLTemplates templates) {
        try {
            mappings.put(Class.forName(className), templates);
        } catch (Exception e) { }
    }
{@code JPAProvider} provides detection of the JPA provider based on the EntityManager instance

@author tiwe
querydsl-jpa/src/main/java/com/querydsl/jpa/impl/JPAProvider.java