def keys(self, full_grid=False):
        keys = super(GridSpace, self).keys()
        if self.ndims == 1 or not full_grid:
            return keys
        dim1_keys = sorted(set(k[0] for k in keys))
        dim2_keys = sorted(set(k[1] for k in keys))
        return [(d1, d2) for d1 in dim1_keys for d2 in dim2_keys]
Returns a complete set of keys on a GridSpace, even when GridSpace isn't fully
dataset/ETHPy150Open ioam/holoviews/holoviews/core/spaces.py/GridSpace.keys