def _checkSkySourceColumnExistence(self, doSkySources):
"""Implements sky_source column checking.
Parameters
----------
doSkySource : `bool`
Value of the config flag determining whether to insert sky sources.
"""
charImConfig = CharacterizeImageConfig()
charImConfig.measurePsf.psfDeterminer = 'piff'
charImConfig.measurePsf.psfDeterminer['piff'].spatialOrder = 0
charImTask = CharacterizeImageTask(config=charImConfig)
charImResults = charImTask.run(self.exposure)
calibConfig = CalibrateConfig()
calibConfig.doAstrometry = False
calibConfig.doPhotoCal = False
calibConfig.doSkySources = doSkySources
calibTask = CalibrateTask(config=calibConfig)
calibResults = calibTask.run(charImResults.exposure)
if doSkySources:
self.assertTrue('sky_source' in calibResults.outputCat.schema.getNames())
else:
self.assertFalse('sky_source' in calibResults.outputCat.schema.getNames())