Same as :func:`~prefix`, for multiple lines.

        :param prefix: Dockerfile command to use, e.g. ``ENV`` or ``RUN``.
        :type prefix: unicode | str
        :param lines: Lines with arguments to be prefixed.
        :type lines: collections.Iterable[unicode | str]

def prefix_all(self, prefix='#', *lines):
        """
        Same as :func:`~prefix`, for multiple lines.

        :param prefix: Dockerfile command to use, e.g. ``ENV`` or ``RUN``.
        :type prefix: unicode | str
        :param lines: Lines with arguments to be prefixed.
        :type lines: collections.Iterable[unicode | str]
        """
        for line in lines:
            if isinstance(line, (tuple, list)):
                self.prefix(prefix, *line)
            elif line:
                self.prefix(prefix, line)
            else:
                self.blank()