def METHOD_NAME(self):
    net = op.network.Demo()
    A = op.phase.StandardLiquid(network=net, species='ethanol')
    B = op.phase.StandardLiquid(network=net, species='h2o')
    vodka = op.phase.LiquidMixture(network=net, components=[A, B])
    vodka.x(A.name, 0.4)
    vodka.x(B.name, 0.6)
    assert len(vodka.components) == 2