def check_contains_non_whitespace(string):
    """If non-white space chars == 0, raise ValueError.

    Used to indicate a string must have at least 1 character
    which is not white space.

    Adheres to the "expected exceptions" protocol by
    referencing expected errors in the 'expected_exceptions'
    attribute of the function.

    Parameters
    ==========
    string (string)
        string to be checked.

    """
    ### XXX
    ### There's still other unicode characters which could
    ### be considered whitespace, that is, characters which
    ### don't have a visual representation. Think of how to
    ### consider them as well

    ### if string doesn't have at least one character which
    ### is not white space, raise ValueError with custom
    ### message
    if not string.strip():

        raise ValueError(
            "string must have at least one character which is"
            " not considered white space"
        )
If non-white space chars == 0, raise ValueError.

    Used to indicate a string must have at least 1 character
    which is not white space.

    Adheres to the "expected exceptions" protocol by
    referencing expected errors in the 'expected_exceptions'
    attribute of the function.

    Parameters
    ==========
    string (string)
        string to be checked.

    
nodezator/ourstdlibs/stringutils.py