code: def test_without_self_loops():
      """Tests for node contraction without preserving -loops."""
      G = nx.cycle_graph(4)
      actual = nx.contracted_nodes(G, 0, 1, self_loops=False)
      expected = nx.complete_graph(3)
      assert nx.is_isomorphic(actual, expected)
  
imports: import pytest
  import networkx
  from networkx.utils import arbitrary_element, edges_equal, nodes_equal
label_desc: Use image node_id 27 for calling a global function with example usage: test_without_self_loops() without return types