def METHOD_NAME(self, trans):
    assert hasattr(trans.fs.unit, "properties_in")
    assert hasattr(trans.fs.unit, "properties_out")
    assert hasattr(trans.fs.unit, "inlet")
    assert len(trans.fs.unit.inlet.vars) == 4
    assert hasattr(trans.fs.unit.inlet, "flow_vol")
    assert hasattr(trans.fs.unit.inlet, "conc_mol_comp")
    assert hasattr(trans.fs.unit.inlet, "temperature")
    assert hasattr(trans.fs.unit.inlet, "pressure")
    assert hasattr(trans.fs.unit, "outlet")
    assert len(trans.fs.unit.outlet.vars) == 4
    assert hasattr(trans.fs.unit.outlet, "flow_mol")
    assert hasattr(trans.fs.unit.outlet, "mole_frac_comp")
    assert hasattr(trans.fs.unit.outlet, "temperature")
    assert hasattr(trans.fs.unit.outlet, "pressure")
    assert number_variables(trans) == 25
    assert number_total_constraints(trans) == 12
    assert number_unused_variables(trans) == 8