dispersion property
      
      double
      get
      dispersion
      
    
    
    
Implementation
double get dispersion => _dispersion;
      
      set
      dispersion
      (double value) 
      
    
    
    
Implementation
set dispersion(double value ) {
	if (_dispersion > 0 != value > 0 ) {
		version ++;
	}
	_dispersion = value;
}