code: public void merkleTree(List<Sha1Hash> tree) {
          sha1_hash_vector v = new sha1_hash_vector();
  
          for (Sha1Hash h : tree) {
              v.push_back(h.swig());
          }
  
          ti.set_merkle_tree(v);
      }
docs: Copies the passed in merkle tree into the torrent info object.
  <p>
  You need to set the merkle tree for a torrent that you've just created
  (as a merkle torrent). The merkle tree is retrieved from the
  {@link #merkleTree()} function, and need to be saved
  separately from the torrent file itself. Once it's added to
  libtorrent, the merkle tree will be persisted in the resume data.
  
  @param tree