pub fn clear_cache(&mut self) {
        self.size = 0;
        self.map.clear();
        self.list.clear();
    }
/// Clear out all stored values and all memory in the cache.
Clear out all stored values and all memory in the cache.
Clear out all stored values and all memory in the cache .
pub fn clear_cache(&mut self) {
        self.size = 0;
        self.map.clear();
        self.list.clear();
    }
pub fn clear_cache ( & mut self ) { self . size = 0 ; self . map . clear ( ) ; self . list . clear ( ) ; }
Clear out all stored values and all memory in the cache.
Clear out all stored values and all memory in the cache .
&mut self