docstr: it should be possible to add multiple edges with different origins
docstr_tok: ["it","should","be","possible","to","add","multiple","edges","with","different","origins"]
code: def test_add_multiple_edges(self):
      """it should be possible to add multiple edges with different origins"""
  
      sm = StructureModel()
      sm.add_edges_from([(1, 2)], origin="unknown")
      sm.add_edges_from([(1, 3)], origin="learned")
      sm.add_edges_from([(1, 4)], origin="expert")
  
      assert (1, 2, "unknown") in sm.edges.data("origin")
      assert (1, 3, "learned") in sm.edges.data("origin")
      assert (1, 4, "expert") in sm.edges.data("origin")
  
imports: import pytest
  from networkx.exception import NodeNotFound
  from causalnex.structure import StructureModel
label_desc: Use image node_id 8 for calling the TestStructureModelAddEdgesFrom obj's underlying member method code with example usage: obj.test_add_multiple_edges() without return types