code: def number_of_nodes(G):
      """Returns the number of nodes in the graph.
  
      This function wraps the :func:`G.number_of_nodes <networkx.Graph.number_of_nodes>` function.
      """
      return G.number_of_nodes()
  
imports: from collections import Counter
  from itertools import chain
  import networkx
  from networkx.utils import not_implemented_for, pairwise
label_desc: Use image node_id 5 for calling a global function with example usage: number_of_nodes(G) and returns: G