code: def handle_input(self, input_hdr):
          
  
          input_slice = input_hdr['NAXIS']*[0]
  
          for i in range(input_hdr['NAXIS']):
              if input_hdr['CTYPE%d'%(i+1)].startswith("RA"):
                  input_slice[-1] = slice(None)
              if input_hdr['CTYPE%d'%(i+1)].startswith("DEC"):
                  input_slice[-2] = slice(None)
  
          return input_slice
docs: This method tries to ensure that the input data has the correct dimensions.
  
          INPUTS:
          input_hdr   (no default)    Header from which data shape is to be extracted.