anchor.diff:  
   Usage example:
   
  -. Create a custom control interface
  +. Create a custom control interface.
   +
   [source,java]
   ----
  
positive.code: }
  ----
  
  [TIP]
  ====
  You can create custom Control interfaces so a set of different Controls provide the same methods and can be accessed with the interface class type.
  ====
  
  [source,java]
  ----
  
negative.code: [TIP]
  ====
  Use the getControl() method on a Spatial to get a specific Control object, and activate its behaviour!
  
  [source,java]
  ----
  ManualControl c = mySpatial.getControl(ManualControl.class);
  c.steerX(steerX);
  ----
  ====
  