def _isna_compat(arr, fill_value=np.nan):
dtype = arr.dtype<EOL>if isna(fill_value):<EOL><INDENT>return not (is_bool_dtype(dtype) or<EOL>is_integer_dtype(dtype))<EOL><DEDENT>return True<EOL>
Parameters
----------
arr: a numpy array
fill_value: fill value, default to np.nan

Returns
-------
True if we can fill using this fill_value