@staticmethod
def content_modification_difference_local(a, b):
    """
        Files are different if a has been modified after b, or, if equal,
        if the file sizes are different.
        :param a: local file
        :param b: remote file
        :return:
        """
    if a['last_modified'] > b['last_modified']:
        return True
    return a['size'] != b['size']
