operator (SymbolicOperator): the operator that will be reordered. must
be a SymbolicOperator or any type of operator that inherits from
SymbolicOperator.
order_function (func): a function per mode that is used to map the
indexing. must have arguments mode index and num_modes.
num_modes (int): default None. User can provide the number of modes
assumed for the system. if None, the number of modes will be
calculated based on the Operator.
reverse (bool): default False. if set to True, the mode mapping is
reversed. reverse = True will not revert back to original if
num_modes calculated differs from original and reverted.