code: public static DataSet<Vertex<Long, String>> getVertices(ExecutionEnvironment env) {
  		List<Vertex<Long, String>> vertices = new ArrayList<>(INPUT_VERTICES.length);
  		for (String vertex : INPUT_VERTICES) {
  			String[] tokens = vertex.split(";");
  			vertices.add(new Vertex<>(Long.parseLong(tokens[0]), tokens[1]));
  		}
  
  		return env.fromCollection(vertices);
  	}
docs: Creates a set of vertices with attached {@link String} values.
  
  @param env execution environment
  @return vertex data set with string values