code: private Collection<IndexedInstance> getInstancesForVertex(Map<String, AttributeValueMap> map, AtlasVertex foundVertex) {
  
          //loop through the unique attributes.  For each attribute, check to see if the vertex property that
          //corresponds to that attribute has a value from one or more of the instances that were passed in.
  
          for(Map.Entry<String, AttributeValueMap> entry : map.entrySet()) {
  
              String propertyName = entry.getKey();
              AttributeValueMap valueMap = entry.getValue();
  
              Object vertexValue = foundVertex.getProperty(propertyName, Object.class);
  
              Collection<IndexedInstance> instances = valueMap.get(vertexValue);
              if(instances != null && instances.size() > 0) {
                  //return first match.  Let the underling graph determine if this is a problem
                  //(i.e. if the other unique attributes change be changed safely to match what
                  //the user requested).
                  return instances;
              }
              //try another attribute
          }
          return Collections.emptyList();
      }
docs: finds the instance(s) that correspond to the given vertex