code: public Map<String, AtlasVertex> getVerticesForPropertyValues(String property, List<String> values) {
  
          if(values.isEmpty()) {
              return Collections.emptyMap();
          }
          Collection<String> nonNullValues = new HashSet<>(values.size());
  
          for(String value : values) {
              if(value != null) {
                  nonNullValues.add(value);
              }
          }
  
          //create graph query that finds vertices with the guids
          AtlasGraphQuery query = graph.query();
          query.in(property, nonNullValues);
          Iterable<AtlasVertex> results = query.vertices();
  
          Map<String, AtlasVertex> result = new HashMap<>(values.size());
          //Process the result, using the guidToIndexMap to figure out where
          //each vertex should go in the result list.
          for(AtlasVertex vertex : results) {
              if(vertex.exists()) {
                  String propertyValue = vertex.getProperty(property, String.class);
                  if(LOG.isDebugEnabled()) {
                      LOG.debug("Found a vertex {} with {} =  {}", string(vertex), property, propertyValue);
                  }
                  result.put(propertyValue, vertex);
              }
          }
          return result;
      }
docs: Finds the Vertices that correspond to the given property values.  Property
  values that are not found in the graph will not be in the map.
  
  @return propertyValue to AtlasVertex map with the result.