Verifies if a string is a valid Base64 encoded string, after replacing '-' with '/'

    :param string string_to_validate:
        String to validate.

    :return:
        Whether given string is a valid base64 string or not.
    :rtype: str

def IsValidBase64String(string_to_validate):
    """Verifies if a string is a valid Base64 encoded string, after replacing '-' with '/'

    :param string string_to_validate:
        String to validate.

    :return:
        Whether given string is a valid base64 string or not.
    :rtype: str
    """
    # '-' is not supported char for decoding in Python(same as C# and Java) which has similar logic while parsing ResourceID generated by backend
    try:
        buffer = base64.standard_b64decode(string_to_validate.replace('-', '/'))
        if len(buffer) != 4:
            return False
    except Exception as e:
        if six.PY2:
            e = e.message
        if type(e) == binascii.Error:
            return False
        else:
            raise e
    return True