code: void findNodes(List<RBBINode> dest, int kind) {
          if (fType == kind) {
              dest.add(this);
          }
          if (fLeftChild != null) {
              fLeftChild.findNodes(dest, kind);
          }
          if (fRightChild != null) {
              fRightChild.findNodes(dest, kind);
          }
      }
docs: -------------------------------------------------------------------------