code: def nx_input():
      g = nx.DiGraph()
      src, dst = edge_pair_input()
      for i, e in enumerate(zip(src, dst)):
          g.add_edge(*e, id=i)
      return g
  
imports: import math
  import numbers
  import backend
  import dgl
  import networkx
  import numpy
  import pytest
  import scipy.sparse
  from dgl import DGLError
label_desc: Use image node_id 2 for calling a global function with example usage: nx_input() and returns: g