code: def _get_exclude_samples(in_file, to_exclude):
      
      include, exclude = [], []
      to_exclude = set(to_exclude)
      for s in get_samples(in_file):
          if s in to_exclude:
              exclude.append(s)
          else:
              include.append(s)
      return include, exclude
docs: Identify samples in the exclusion list which are actually in the VCF.