code: def test_monomorphism_iter1():
      g1 = nx.DiGraph()
      g2 = nx.DiGraph()
      g1.add_edge("A", "B")
      g1.add_edge("B", "C")
      g1.add_edge("C", "A")
      g2.add_edge("X", "Y")
      g2.add_edge("Y", "Z")
      gm12 = iso.DiGraphMatcher(g1, g2)
      x = list(gm12.subgraph_monomorphisms_iter())
      assert {"A": "X", "B": "Y", "C": "Z"} in x
      assert {"A": "Y", "B": "Z", "C": "X"} in x
      assert {"A": "Z", "B": "X", "C": "Y"} in x
      assert len(x) == 3
      gm21 = iso.DiGraphMatcher(g2, g1)
      # Check if StopIteration exception returns False
      assert not gm21.subgraph_is_monomorphic()
  
imports: import importlib.resources
  import os
  import random
  import struct
  import networkx
  from networkx.algorithms import isomorphism
label_desc: Use image node_id 5 for calling a global function with example usage: test_monomorphism_iter1() without return types