Step Arguments
==============
The ``saturation`` step has one optional argument:

``--n_pix_grow_sat`` (integer, default=1)
  The distance to use when growing saturation flag values to neighboring pixels,
  in order to account for charge migration (spilling). The total region size is
  2*n_pix_grow_sat+1 pixels, centered on the primary pixel.

``--use_readpatt`` (boolean, default=True)
  Use information about the readout pattern for grouped data to perform additional
  checks to find data that saturates mid-group.  This can be important for
  finding extremely bright cosmic rays that saturate in group 2.