config(configs) {
    for (const key in configs) {
      if (key) {
        this.configuration[key] = key === 'default'
          ? configs[key]
          : Object.assign({}, this.configuration.default, configs[key]);
      }
    }
  }
@method config
@description Load configurations from object.
@param {Object} configs Configuration data
@memberof module:modules/app.StateModule
@example <caption> Adding `green` configuration</caption>
state.config({
  green: {
    sphereColor: 0x00ff00,
    planeColor: 0x00ff00
  }
});