docs: public List<InternalDocumentRevision> getPathForNode(long sequence) {
          Misc.checkArgument(sequenceMap.containsKey(sequence),
                  "DocumentRevision for that sequence must be in the tree already.");
          DocumentRevisionNode l = sequenceMap.get(sequence);
          List<InternalDocumentRevision> r = new LinkedList<InternalDocumentRevision>();
          while(l != null) {
              r.add(l.getData());
              if(l.getData().getParent() > 0) {
                  l = sequenceMap.get(l.getData().getParent());
              } else {
                  l = null;
              }
          }
  
          return r;
      }