def seek(self, layer):
        # seek to given layer (1..max)
        if layer == self.frame:
            return
        try:
            if layer <= 0:
                raise IndexError
            name, mode, bbox, tile = self.layers[1-layer]
            self.mode = mode
            self.tile = tile
            self.frame = layer
            self.fp = self._fp
            return name, bbox
        except IndexError:
            raise EOFError, "no such layer"
dataset/ETHPy150Open kleientertainment/ds_mod_tools/pkg/win32/Python27/Lib/site-packages/PIL/PsdImagePlugin.py/PsdImageFile.seek/swapped operands of `-`