code: function(key, value){
      var c = getCache(this.ns)
  
      // set({foo: "bar"})
      if(arguments.length === 1 && typeof key === "object") {
        Object.keys(key).forEach(function(k){
          c[k] = key[k]
        }, this)
      }
  
      // set("foo", "bar")
      else {
        c[key] = value
      }
  
      return setCache(this.ns, c)
    }
docs: setter
  
  @param {String|Object} key   key or an {key: value} object
  @param {Object} value value if first parameter is a key