code: double computeAssessment(MathNode refTree, MathNode compTree) {
          int absDiff = Math.abs(refTree.getDepth() - compTree.getDepth());
          int maxDepth = compTree.getMaxDepth() + 1;
          double depthWeight = 1 - (double) absDiff / (double) maxDepth;
          return depthWeight * coverage;
      }
docs: This method is still in testing.
  <br/>
  This method assesses the similarity value between two partial trees.
  The measurement consists of a product from their depth and coverage distance.
  
  @param refTree  partial reference tree (or full tree)
  @param compTree partial comparison tree (or full tree)
  @return value between 0 to 1, 1 is a full-match