code: def test_nonexisting_edgekey_raises(self):
      with pytest.raises(nx.exception.NetworkXError):
          nx.from_pandas_edgelist(
              self.df,
              source="source",
              target="target",
              edge_key="Not_real",
              edge_attr=True,
              create_using=nx.MultiGraph(),
          )
  
imports: import pytest
  import networkx
  from networkx.utils import edges_equal, graphs_equal, nodes_equal
label_desc: Use image node_id 20 for calling the TestConvertPandas obj's underlying member method code with example usage: obj.test_nonexisting_edgekey_raises() without return types