code: def getTemplates(fnames, blend=True):
      
      if not blend:
          newhdrs =  blendheaders.getSingleTemplate(fnames[0])
          newtab = None
      else:
          # apply rules to create final version of headers, plus table
          newhdrs, newtab = blendheaders.get_blended_headers(inputs=fnames)
  
      cleanTemplates(newhdrs[1],newhdrs[2],newhdrs[3])
  
      return newhdrs, newtab
docs: Process all headers to produce a set of combined headers
          that follows the rules defined by each instrument.