97     def __call__(self, *args, **kw):  argument
99         res = res._add_vars(kw)
108     def attr(self, **kw):  argument
109         for key in kw.keys():
111                 kw[key[:-1]] = kw[key]
112                 del kw[key]
114         new_attrs.update(kw)
119     def param(self, **kw):  argument
121         new_params.update(kw)
142     def var(self, **kw):  argument
143         kw = self.coerce_vars(kw)
144         new_vars = self.vars + list(kw.items())
149     def setvar(self, **kw):  argument
155         kw = self.coerce_vars(kw)
158             if name in kw:
161         new_vars.extend(kw.items())
166     def setvars(self, **kw):  argument
171         return self.__class__(self.url, vars=kw.items(),