bp_test/out/substitute_vals.out.3

   1 SEQ: AGCTTTTCATTCTGACTGCAACGGGCAATACCTGCCGTGAGTAAATNNN
   2 SEQ_LEN: 50
   3 SEQ_NAME: test1
   4 ---
   5 SEQ: TGGGCGTTNNNNGCAGGTAAATAGGCTTCTGTNNGACGTACTATAACGT
   6 SEQ_LEN: 50
   7 SEQ_NAME: test2
   8 ---
   9 SEQ: NNNATAGTACTACAGTAACGAAAGTCNNGGATTTTTCTGAAGAGCTTTA
  10 SEQ_LEN: 50
  11 SEQ_NAME: test3
  12 ---