old_contents: def make_overscan_test_files(test_dir):
      """
      Creates two files, one with overscan, one without for Alta U9
  
      Parameters
  
      test_dir: str
          Directory in which to create the overscan files.
  
      Returns
  
      info: list
          (working_dir, has_oscan, has_no_oscan)
          working_dir: str
              subdirectory of test_dir in which files are created
          has_oscan: str
              Name of FITS file that has overscan region
          has_no_oscan: str
              Name of FITS file that has no overscan region
      """
      from ..feder import ApogeeAltaU9
      from os import path, mkdir, chdir
      import pyfits
      import numpy as np
  
      has_oscan = 'yes_oscan.fit'
      has_no_oscan = 'no_oscan.fit'
      apogee = ApogeeAltaU9()
      working_dir = 'overscan_test'
      mkdir(path.join(test_dir, working_dir))
      chdir(path.join(test_dir, working_dir))
      no_oscan = np.zeros([apogee.rows, apogee.overscan_start])
      add_instrument = lambda hdr: hdr.update('instrume', 'Apogee Alta')
      hdu = pyfits.PrimaryHDU(no_oscan)
      add_instrument(hdu.header)
      hdu.writeto(has_no_oscan)
      yes_oscan = np.zeros([apogee.rows, apogee.columns])
      hdu = pyfits.PrimaryHDU(yes_oscan)
      add_instrument(hdu.header)
      hdu.writeto(has_oscan)
      chdir(test_dir)
      return (working_dir, has_oscan, has_no_oscan)
  
new_contents: def make_overscan_test_files(test_dir):
      """
      Creates two files, one with overscan, one without for Alta U9
  
      Parameters
  
      test_dir: str
          Directory in which to create the overscan files.
  
      Returns
  
      info: list
          (working_dir, has_oscan, has_no_oscan)
          working_dir: str
              subdirectory of test_dir in which files are created
          has_oscan: str
              Name of FITS file that has overscan region
          has_no_oscan: str
              Name of FITS file that has no overscan region
      """
      from ..feder import ApogeeAltaU9
      from os import path, mkdir, chdir
      import pyfits
      import numpy as np
  
      has_oscan = 'yes_oscan.fit'
      has_no_oscan = 'no_oscan.fit'
      apogee = ApogeeAltaU9()
      working_dir = 'overscan_test'
      mkdir(path.join(test_dir, working_dir))
      chdir(path.join(test_dir, working_dir))
      no_oscan = np.zeros([apogee.rows, apogee.overscan_start])
      add_instrument = lambda hdr: hdr.set('instrume', 'Apogee Alta')
      hdu = pyfits.PrimaryHDU(no_oscan)
      add_instrument(hdu.header)
      hdu.writeto(has_no_oscan)
      yes_oscan = np.zeros([apogee.rows, apogee.columns])
      hdu = pyfits.PrimaryHDU(yes_oscan)
      add_instrument(hdu.header)
      hdu.writeto(has_oscan)
      chdir(test_dir)
      return (working_dir, has_oscan, has_no_oscan)
  
subject: Replace pyfits header.update with header.set