old_contents: import numpy as np
  from astropy.io import fits
  import tempfile
  import warnings
  
  
  def make_casa_mask(SpecCube, outname, append_to_image=True,
                     img=""):
      '''
      Takes a SpectralCube object as an input. Outputs the mask in a CASA
      friendly form.
  
      Parameters
      ----------
      SpecCube : SpectralCube
          SpectralCube object containing mask.
      outname : str
          Name of the outputted mask file.
      append_to_image : bool, optional
          Appends the mask to a given image.
      img : str, optional
          Image to be appended to. Must be specified if append_to_image is
          enabled.
      '''
  
      try:
          from taskinit import ia
          from tasks import immath
      except ImportError:
          print("Run in CASA! Cannot import casac.")
  
      # Get the header info from the image
      # There's not wcs_astropy2casa (yet), so create a temporary file for
      # CASA to open.
      temp = tempfile.NamedTemporaryFile()
      # CASA is closing this file at some point so set it to manual delete.
      temp2 = tempfile.NamedTemporaryFile(delete=False)
  
      hdu = fits.PrimaryHDU(header=SpecCube.header,
                            data=np.empty(SpecCube.shape))
  
      hdu.writeto(temp.name)
  
      ia.fromfits(infile=temp.name, outfile=temp2.name, overwrite=True)
  
      temp.close()
  
      cs = ia.coordsys()
  
      ia.close()
  
      temp2.close()
  
      mask_arr = SpecCube.mask.include()
  
      # CASA doesn't like bool? Using floats for now...
      ia.newimagefromarray(outfile=outname,
                           pixels=mask_arr.astype('float64'))
  
      ia.open(outname)
      ia.setcoordsys(cs.torecord())
  
      ia.close()
  
      if append_to_image:
          warnings.warn("Image appending not working yet.")
          # immath(imagename=img, mode='evalexpr', expr='IM0',
          #        outfile=img+"_test", mask='mask('+outname+')')
  
new_contents: import numpy as np
  from astropy.io import fits
  import tempfile
  import warnings
  
  
  def make_casa_mask(SpecCube, outname, append_to_image=True,
                     img=None):
      '''
      Takes a SpectralCube object as an input. Outputs the mask in a CASA
      friendly form.
  
      Parameters
      ----------
      SpecCube : SpectralCube
          SpectralCube object containing mask.
      outname : str
          Name of the outputted mask file.
      append_to_image : bool, optional
          Appends the mask to a given image.
      img : str, optional
          Image to be appended to. Must be specified if append_to_image is
          enabled.
      '''
  
      try:
          from taskinit import ia
          from tasks import immath
      except ImportError:
          print("Cannot import casac. Must be run in a CASA environment.")
  
      # Get the header info from the image
      # There's not wcs_astropy2casa (yet), so create a temporary file for
      # CASA to open.
      temp = tempfile.NamedTemporaryFile()
      # CASA is closing this file at some point so set it to manual delete.
      temp2 = tempfile.NamedTemporaryFile(delete=False)
  
      hdu = fits.PrimaryHDU(header=SpecCube.header,
                            data=np.empty(SpecCube.shape))
  
      hdu.writeto(temp.name)
  
      ia.fromfits(infile=temp.name, outfile=temp2.name, overwrite=True)
  
      temp.close()
  
      cs = ia.coordsys()
  
      ia.close()
  
      temp2.close()
  
      mask_arr = SpecCube.mask.include()
  
      # CASA doesn't like bool? Using floats for now...
      ia.newimagefromarray(outfile=outname,
                           pixels=mask_arr.astype('float64'))
  
      ia.open(outname)
      ia.setcoordsys(cs.torecord())
  
      ia.close()
  
      if append_to_image:
          if img is None:
              raise TypeError("img argument must be specified to append the mask.")
          warnings.warn("Image appending not working yet.")
          # immath(imagename=img, mode='evalexpr', expr='IM0',
          #        outfile=img+"_test", mask='mask('+outname+')')
  
subject: Check for inputted image.