code: def _check_samples_line(klass, arr):
          
          if len(arr) <= len(REQUIRE_NO_SAMPLE_HEADER):
              if tuple(arr) != REQUIRE_NO_SAMPLE_HEADER:
                  raise exceptions.IncorrectVCFFormat(
                      "Sample header line indicates no sample but does not "
                      "equal required prefix {}".format("\t".join(REQUIRE_NO_SAMPLE_HEADER))
                  )
          elif tuple(arr[: len(REQUIRE_SAMPLE_HEADER)]) != REQUIRE_SAMPLE_HEADER:
              raise exceptions.IncorrectVCFFormat(
                  'Sample header line (starting with "#CHROM") does not '
                  "start with required prefix {}".format("\t".join(REQUIRE_SAMPLE_HEADER))
              )
docs: Peform additional check on samples line