public SetDomainCacheTTLRequest addCacheTTL(CacheTTL rule) {
        if (cacheTTL == null) {
            cacheTTL = new ArrayList<CacheTTL>();
        }
        cacheTTL.add(rule);
        return this;
    }
public SetDomainCacheTTLRequest addCacheTTL ( CacheTTL rule ) { if ( cacheTTL == null ) { cacheTTL = new ArrayList < CacheTTL > ( ) ; } cacheTTL . add ( rule ) ; return this ; }
@param rule
@return returns this object