def getConfiguration(self, **scalars):
        red = int(scalars.get('red', 1))
        ir = int(scalars.get('ir', 2))

        return {
          'extractBands': (1 - red, ir - 1),    # extract only the two bands corresponding to user-specified red and infrared band indexes.
          'compositeRasters': False,            # input is a single raster, band compositing doesn't apply.
          'inheritProperties': 4 | 8,           # inherit all but the pixel type and NoData from the input raster
          'invalidateProperties': 2 | 4 | 8,    # reset any statistics and histogram that might be held by the parent dataset (because this function modifies pixel values). 
          'inputMask': False                    # Don't need input raster mask in .updatePixels().
        }
dataset/ETHPy150Open Esri/raster-functions/functions/NDVI.py/NDVI.getConfiguration/swapped operands of `-`