(sentence)
:param sentence: str a sentence to clean of leading and trailing space characters.
    :return: str a sentence that has been cleaned of leading and trailing space characters.
def clean_up_spacing(sentence):
    """

    :param sentence: str a sentence to clean of leading and trailing space characters.
    :return: str a sentence that has been cleaned of leading and trailing space characters.
    """

    pass
def clean_up_spacing ( sentence ) : pass