def _isna_old(obj):
if is_scalar(obj):<EOL><INDENT>return libmissing.checknull_old(obj)<EOL><DEDENT>elif isinstance(obj, ABCMultiIndex):<EOL><INDENT>raise NotImplementedError("<STR_LIT>")<EOL><DEDENT>elif isinstance(obj, (ABCSeries, np.ndarray, ABCIndexClass)):<EOL><INDENT>return _isna_ndarraylike_old(obj)<EOL><DEDENT>elif isinstance(obj, ABCGeneric):<EOL><INDENT>return obj._constructor(obj._data.isna(func=_isna_old))<EOL><DEDENT>elif isinstance(obj, list):<EOL><INDENT>return _isna_ndarraylike_old(np.asarray(obj, dtype=object))<EOL><DEDENT>elif hasattr(obj, '<STR_LIT>'):<EOL><INDENT>return _isna_ndarraylike_old(np.asarray(obj))<EOL><DEDENT>else:<EOL><INDENT>return obj is None<EOL><DEDENT>
Detect missing values. Treat None, NaN, INF, -INF as null.

    Parameters
    ----------
    arr: ndarray or object value

    Returns
    -------
    boolean ndarray or boolean