code: def merge_sketches(outdir, sketch_paths):
      
      merge_sketch_path = os.path.join(outdir, 'sistr.msh')
      args = ['mash', 'paste', merge_sketch_path]
      for x in sketch_paths:
          args.append(x)
      args.append(MASH_SKETCH_FILE)
      logging.info('Running Mash paste with command: %s', ' '.join(args))
      p = Popen(args)
      p.wait()
      assert os.path.exists(merge_sketch_path), 'Merged sketch was not created at {}'.format(merge_sketch_path)
      return merge_sketch_path
docs: Merge new Mash sketches with current Mash sketches
  
      Args:
          outdir (str): output directory to write merged Mash sketch file
          sketch_paths (list of str): Mash sketch file paths for input fasta files
  
      Returns:
          str: output path for Mash sketch file with new and old sketches