func (c *cache) SetDefault(k string, x interface{}) {
	c.Set(k, x, DefaultExpiration)
}
func (c *cache) SetDefault(k string, x interface{}) {
	c.Set(k, x, DefaultExpiration)
}
func ( c * cache ) SetDefault ( k string , x interface { } ) { c . Set ( k , x , DefaultExpiration ) }
// Add an item to the cache, replacing any existing item, using the default
// expiration.
Add an item to the cache replacing any existing item using the default expiration .