code: @Override
      public String vertexMatchPredicate(String alias) {
          Objects.requireNonNull(alias, "alias cannot be null");
          // check we require predicate, if only one label in partition we use match pattern
          if (labels.size() != 1) {
              // match predicate where at least one vertex label must be present in partition (alias:`label1` OR alias:`label2` ... alias.`labeln`)
              return labels.stream().map(label -> alias + ":`" + label + "`").collect(Collectors.joining(" OR ", "(", ")"));
          }
          return null;
      }
docs: Generates a {@link org.apache.tinkerpop.gremlin.structure.Vertex} Cypher MATCH predicate, example:
  <p>
  (alias:Label1 OR alias:Label2)
  </p>
  
  @param alias The vertex alias in the MATCH Cypher statement.
  @return The Cypher MATCH predicate if required by the vertex, otherwise <code>null</code>.