public void DefaultIfEmpty_WithWhitespaceStringAndDoIgnoreWhitespace_ExpectsDefaultString() => Equal( SENTENCE, SENTENCE_WHITESPACE.DefaultIfEmpty(SENTENCE, true));
public void DefaultIfEmpty_WithWhitespaceStringAndNotIgnoreWhitespace_ExpectsWhitespaceString() => Equal( SENTENCE_WHITESPACE, SENTENCE_WHITESPACE.DefaultIfEmpty(SENTENCE, false));