code: function(key, map, init) {
              this._configs = this._configs || {};
              map = map || {};
              if (!this._configs[key]) {
                  map.name = key;
                  this._configs[key] = this.createAttribute(map);
              } else {
                  this._configs[key].configure(map, init);
              }
          }
docs: Sets or updates an Attribute instance's properties.
  @method setAttributeConfig
  @param {String} key The attribute's name.
  @param {Object} map A key-value map of attribute properties
  @param {Boolean} init Whether or not this should become the intial config.