def __init__(self, piping_method, *args):
self.__piping_method = piping_method<EOL>if args and isinstance(args[<NUM_LIT:0>], dataframe.DataFrame):<EOL><INDENT>raise PipingException("<STR_LIT>")<EOL><DEDENT>elif not args:<EOL><INDENT>raise ValueError("<STR_LIT>")<EOL><DEDENT>else:<EOL><INDENT>self.__args = args<EOL><DEDENT>
Constructor for chainable. Takes a tuple which is either a dataframe
and column names to group by or only the column names

:param args: tuple of params