How to use the siuba.siu.BinaryOp function in siuba

def __call__(self, *args, **kwargs):
        call = Call('__call__',
                    BinaryOp('__getattr__', MetaArg("_"), self.name),
                    *args,
                    **kwargs
                    )

        return self.to_copy(name = call)

def __getattr__(self, x):
        # temporary hack working around ipython pretty.py printing
        #if x == "__class__": return Symbolic

        return Symbolic(BinaryOp(
                "__getattr__",
                self.__source,
                strip_symbolic(x)
                ))

def needs_paren(self, x):
        if isinstance(x, BinaryOp):
            sub_lvl = BINARY_LEVELS[x.func]
            level = BINARY_LEVELS[self.func]
            if sub_lvl != 0 and sub_lvl > level:
                return True

        return False

def _binary_op(self, x):
        if left_assoc:
            node = BinaryOp(op_name, strip_symbolic(self), strip_symbolic(x))
        else:
            node = BinaryOp(op_name, strip_symbolic(x), strip_symbolic(self))

        return Symbolic(node, ready_to_call = True)
    return _binary_op

def __getitem__(self, x):
        return Symbolic(BinaryOp(
                "__getitem__",
                self.__source,
                slice_to_call(x),
                ),
                ready_to_call = True)