code: private Property<CircularProgressDrawable, Float> createSweepProperty() {
          return new Property<CircularProgressDrawable, Float>(Float.class, "arc") {
  
              @Override
              public Float get(final CircularProgressDrawable object) {
                  return currentSweepAngle;
              }
  
              @Override
              public void set(final CircularProgressDrawable object, final Float value) {
                  currentSweepAngle = value;
                  invalidateSelf();
              }
  
          };
      }
docs: Creates and returns a property, which allows to animate the sweep angle of the progress
  drawable.
  
  @return The property, which has been created, as an instance of the class {@link Property}