@property
    def ddims(self):
        dimensions = []
        dimension_names = []
        for el in self:
            for dim in el.dimensions():
                if dimension_names not in dim.name:
                    dimensions.append(dim)
                    dimension_names.append(dim.name)
        return dimensions
dataset/ETHPy150Open ioam/holoviews/holoviews/core/overlay.py/Overlay.ddims/swapped operands of `not in`