code: public Graph<K, VV, EV> removeVertex(Vertex<K, VV> vertex) {
  
  		List<Vertex<K, VV>> vertexToBeRemoved = new ArrayList<>();
  		vertexToBeRemoved.add(vertex);
  
  		return removeVertices(vertexToBeRemoved);
  	}
docs: Removes the given vertex and its edges from the graph.
  
  @param vertex the vertex to remove
  @return the new graph containing the existing vertices and edges without
  the removed vertex and its edges