code: def saveToFile(self,imageObjectList):
          
          virtual = imageObjectList[0].inmemory
  
          for key in self.masklist.keys():
              #check to see if the file already exists on disk
              filename = self.masknames[key]
              #create a new fits image with the mask array and a standard header
              #open a new header and data unit
              newHDU = fits.PrimaryHDU()
              newHDU.data = self.masklist[key]
  
              if virtual:
                  for img in imageObjectList:
                      img.saveVirtualOutputs({filename:newHDU})
  
              else:
                  try:
                      newHDU.writeto(filename, overwrite=True)
                      log.info("Saving static mask to disk: %s" % filename)
  
                  except IOError:
                      log.error("Problem saving static mask file: %s to "
                                "disk!\n" % filename)
                      raise IOError
docs: Saves the static mask to a file
              it uses the signatures associated with each
              mask to contruct the filename for the output mask image.