anchor.diff:        _body.angularDamping = angularDampening;
     }
   
  -  bool allowSleep;
  -
  -  bool awake;
  -
  -  bool fixedRotation;
  -
  -  bool bullet;
  -
  -  bool active;
  +  bool _allowSleep;
  +
  +  bool get allowSleep => _allowSleep;
  +
  +  set allowSleep(bool allowSleep) {
  +    _allowSleep = allowSleep;
  +
  +    if (_body != null)
  +      _body.setSleepingAllowed(allowSleep);
  +  }
  +
  +  bool _awake;
  +
  +  bool get awake {
  +    if (_body != null)
  +      return _body.isAwake();
  +    else
  +      return _awake;
  +  }
  +
  +  set awake(bool awake) {
  +    _awake = awake;
  +
  +    if (_body != null)
  +      _body.setAwake(awake);
  +  }
  +
  +  bool _fixedRotation;
  +
  +  bool get fixedRotation => _fixedRotation;
  +
  +  set fixedRotation(bool fixedRotation) {
  +    _fixedRotation = fixedRotation;
  +
  +    if (_body != null)
  +      _body.setFixedRotation(fixedRotation);
  +  }
  +
  +  bool _bullet;
  +
  +  bool get bullet => _bullet;
  +
  +  set bullet(bool bullet) {
  +    _bullet = bullet;
  +
  +    if (_body != null) {
  +      _body.setBullet(bullet);
  +    }
  +  }
  +
  +  bool _active;
  +
  +  bool get active {
  +    if (_body != null)
  +      return _body.isActive();
  +    else
  +      return _active;
  +  }
  +
  +  set active(bool active) {
  +    _active = active;
  +
  +    if (_body != null)
  +      _body.setActive(active);
  +  }
   
     double gravityScale;
   
  
positive.code:     double angularVelocity: 0.0,
      this.linearDampening: 0.0,
      double awakeangularDampening: 0.0,
      this.allowSleep: true,
      this.awake: true,
      this.fixedRotation: false,
      this.bullet: false,
      this.active: true,
      this.gravityScale: 1.0
    }) {
      this.density = density;
  
negative.code:     this.linearVelocity = linearVelocity;
      this.angularVelocity = angularVelocity;
      this.angularDampening = angularDampening;
  
      this.allowSleep = allowSleep;
      this.awake = awake;
      this.fixedRotation = fixedRotation;
      this.bullet = bullet;
      this.active = active;
    }
  
    Object tag;
  