def METHOD_NAME(
    observables_list: list[BaseOperator | PauliSumOp],
) -> list[BaseOperator | PauliSumOp]:
    """Replaces all occurrence of operators equal to 0 in the list with an equivalent ``PauliSumOp``
    operator."""
    if observables_list:
        zero_op = SparsePauliOp.from_list([("I" * observables_list[0].num_qubits, 0)])
        for ind, observable in enumerate(observables_list):
            if observable == 0:
                observables_list[ind] = zero_op
    return observables_list