code: protected void actionExtracting(double extrp)
      {
          if (extractable == null || extractable.getResourceQuantity() > 0)
          {
              if (extractable != null)
              {
                  progress += Math.min(extractable.getResourceQuantity(), speed * extrp);
              }
              else
              {
                  progress += speed * extrp;
              }
              final int curProgress = Math.min((int) Math.floor(progress), extractionCapacity);
  
              // Check increases
              if (curProgress > lastProgress)
              {
                  extract(curProgress);
              }
          }
      }
docs: Action called from update extraction in extract state.
  
  @param extrp extrapolation value.