Abstract Cache of Ballerina

abstract-cache.bal

public type AbstractCache abstract object {
    public function put(string key, any value, int maxAgeInSeconds = -1) returns Error?;
    public function get(string key) returns any|Error;
    public function invalidate(string key) returns Error?;
    public function invalidateAll() returns Error?;
    public function hasKey(string key) returns boolean;
    public function keys() returns string[];
    public function size() returns int;
    public function capacity() returns int;
};