private Mutation createMutationForVertex(AccumuloVertex vertex) {
   String vertexRowKey = vertex.getId();
   Mutation m = new Mutation(vertexRowKey);
   m.put(
       AccumuloVertex.CF_SIGNAL,
       EMPTY_TEXT,
       visibilityToAccumuloVisibility(vertex.getVisibility()),
       vertex.getTimestamp(),
       EMPTY_VALUE);
   for (PropertyDeleteMutation propertyDeleteMutation : vertex.getPropertyDeleteMutations()) {
     addPropertyDeleteToMutation(m, propertyDeleteMutation);
   }
   for (PropertySoftDeleteMutation propertySoftDeleteMutation :
       vertex.getPropertySoftDeleteMutations()) {
     addPropertySoftDeleteToMutation(m, propertySoftDeleteMutation);
   }
   for (Property property : vertex.getProperties()) {
     addPropertyToMutation(vertex.getGraph(), m, vertexRowKey, property);
   }
   return m;
 }
 public Iterable<KeyValuePair> getKeyValuePairsForVertex(AccumuloVertex vertex) {
   List<KeyValuePair> results = new ArrayList<>();
   Text vertexRowKey = new Text(vertex.getId());
   results.add(
       new KeyValuePair(
           new Key(
               vertexRowKey,
               AccumuloVertex.CF_SIGNAL,
               ElementMutationBuilder.EMPTY_TEXT,
               visibilityToAccumuloVisibility(vertex.getVisibility()),
               vertex.getTimestamp()),
           EMPTY_VALUE));
   if (vertex.getPropertyDeleteMutations().iterator().hasNext()) {
     throw new VertexiumException("Cannot get key/value pairs for property deletions");
   }
   for (PropertySoftDeleteMutation propertySoftDeleteMutation :
       vertex.getPropertySoftDeleteMutations()) {
     addPropertySoftDeleteToKeyValuePairs(results, vertexRowKey, propertySoftDeleteMutation);
   }
   for (Property property : vertex.getProperties()) {
     addPropertyToKeyValuePairs(results, vertexRowKey, property);
   }
   return results;
 }