def __init__(self, *columns, **kwargs):
if not all([isinstance(c, Column) for c in columns]):<EOL><INDENT>raise TypeError('<STR_LIT>')<EOL><DEDENT>self.type = '<STR_LIT>'<EOL>self.columns = columns<EOL>
Init method.

Args:
    *columns (): the instances of Column.
    **kwargs (): not used.