code: function(fullName) {
          Ember.assert('fullName must be a proper full name', validateFullName(fullName));
  
          var normalizedName = this.normalize(fullName);
  
          delete this.registry[normalizedName];
          delete this.cache[normalizedName];
          delete this.factoryCache[normalizedName];
          delete this.resolveCache[normalizedName];
          delete this._options[normalizedName];
        }
docs: Unregister a fullName
  
  ```javascript
  var container = new Container();
  container.register('model:user', User);
  
  container.lookup('model:user') instanceof User //=> true
  
  container.unregister('model:user')
  container.lookup('model:user') === undefined //=> true
  ```
  
  @method unregister
  @param {String} fullName