def set(self, key_, **kwargs):
        stored = self.get(key_, dict())
        changed = False
        for k, v in kwargs.items():
            if k not in stored or stored[k] != v:
                stored[k] = v
                changed = True
        if changed:
            self[key_] = stored
Return gradient position f in [0..1] for x-index Idx in
dataset/ETHPy150Open gawel/irc3/irc3/plugins/storage.py/Storage.set--crossover with--dataset/ETHPy150Open enthought/mayavi/tvtk/util/tk_gradient_editor.py/FunctionControl.Channel.get_index_pos