old_contents: from openff.toolkit.topology import Molecule
  from openff.toolkit.typing.engines.smirnoff.forcefield import ForceField
  
  
  def test_basic_construction():
      top = Molecule.from_smiles("C").to_topology()
      parsley = ForceField("openff-1.0.0.offxml")
      out = parsley._to_interchange(top)
  
      assert out.topology is not None
      assert out.topology.mdtop is not None
      assert out.positions is None
      for key in ["vdW", "Bonds", "ProperTorsions", "Electrostatics"]:
          assert key in out.handlers
  
new_contents: from openff.toolkit.tests.utils import requires_pkg
  from openff.toolkit.topology import Molecule
  from openff.toolkit.typing.engines.smirnoff.forcefield import ForceField
  
  
  @requires_pkg("openff.interchange")
  def test_basic_construction():
      top = Molecule.from_smiles("C").to_topology()
      parsley = ForceField("openff-1.0.0.offxml")
      out = parsley._to_interchange(top)
  
      assert out.topology is not None
      assert out.topology.mdtop is not None
      assert out.positions is None
      for key in ["vdW", "Bonds", "ProperTorsions", "Electrostatics"]:
          assert key in out.handlers
  
subject: Add @requires_pkg on Interchange tests (#1054)