docstr: should be possible to specify origin during init
docstr_tok: ["should","be","possible","to","specify","origin","during","init"]
code: def test_init_with_origin(self):
      """should be possible to specify origin during init"""
  
      sm = StructureModel([(1, 2)], origin="learned")
      assert (1, 2, "learned") in sm.edges.data("origin")
  
imports: import pytest
  from networkx.exception import NodeNotFound
  from causalnex.structure import StructureModel
label_desc: Use image node_id 2 for calling the TestStructureModel obj's underlying member method code with example usage: obj.test_init_with_origin() without return types