def palindrome_sentence(sentence: str) -> bool:
    """
    Check if a sentence is a palindrome.
    The function ignores whitespace, capitalisation and
    punctuation in the sentence.
    :param sentence: The sentence to check.
    :return: True if `sentence` is a palindrome, False otherwise.
    """
    string = ""
    for char in sentence:
        if char.isalnum():
             string += char
             # print(string)
    return string[::-1].casefold() == string.casefold()