public interface Measurable
{
   double getMeasure();  // An abstract method

   static double average(Measurable[] objects) // A static method
   {
      double sum = 0;
      for (Measurable obj : objects)
      {
         sum = sum + obj.getMeasure();
      }
      if (objects.length > 0) { return sum / objects.length; }
      else { return 0; }
   } 
}