class LightFixture
{
  bulb
  {  
     On 
     { 
       flip -> Off;
     }
       Off 
     { 
       flip -> On; 
     }
  }

  AnotherBulb
  {  
     On 
     { 
       flip -> Off;
     }
       Off 
     { 
       flip -> On; 
     }
  }
}