Apply anti-commutative property of the commutator to apply a standard
    ordering of the commutator arguments

def commutator_order(cls, ops, kwargs):
    """Apply anti-commutative property of the commutator to apply a standard
    ordering of the commutator arguments
    """
    from qnet.algebra.core.operator_algebra import Commutator
    assert len(ops) == 2
    if cls.order_key(ops[1]) < cls.order_key(ops[0]):
        return -1 * Commutator.create(ops[1], ops[0])
    else:
        return ops, kwargs