code: public static void addProperty(AtlasVertex vertex, String propertyName, Object value) {
          String actualPropertyName = GraphHelper.encodePropertyKey(propertyName);
  
          if (LOG.isDebugEnabled()) {
              LOG.debug("Adding property {} = \"{}\" to vertex {}", actualPropertyName, value, string(vertex));
          }
  
          vertex.addProperty(actualPropertyName, value);
      }
docs: Adds an additional value to a multi-property.
  
  @param vertex
  @param propertyName
  @param value