text: 
  phina.namespace(function() {
  
    /**
     * @class phina.asset.AssetManager
     * 
     */
    phina.define('phina.asset.AssetManager', {
      _static: {
        assets: {
          image: {},
          sound: {},
          spritesheet: {},
        },
        
        get: function(type, key) {
          return this.assets[type] && this.assets[type][key];
        },
        set: function(type, key, asset) {
          if (!this.assets[type]) {
            this.assets[type] = {};
          }
          this.assets[type][key] = asset;
        },
        contains: function(type, key) {
          return ;
        }
      },
  
    });
  
  });
  
  