>test <trap> ab > cd
UACACUGUGGAUCCGGUGAGGUAGUAGGUUGUAUAGUUUGGAAUAUUACCACCGGUGAAC
UAUGCAAUUUUCUACCUUACCGGAGACAGAACUCUUCGA
>cel-lin-4 MI0000002 Caenorhabditis elegans lin-4 stem-loop
AUGCUUCCGGCCUGUUCCCUGAGACCUCAAGUGUGAGUGUACUAUUGAUGCUUCACACCU
GGGCUCUCCGGGUACCAGGACGGUUUGAGCAGAU
>cel-mir-46 MI0000017 Caenorhabditis elegans miR-46 stem-loop
CUGAGGUGAAGCUGAAGAGAGCCGUCUAUUGACAGUUCAAGACCACGAGUCGUUGUGUGC
GGUAUCAGGAAGUGGGCAACCGCCUCCAGACGCCGAGAAGCUGGUCAAACUUGGUCAUUUAGAGGAAGUAAAAGUCGUAA
CAAGGUUUCCGUAGGUGAACUGCGGA
>record with no sequence
>U51103.1.1480 Bacteria;Proteobacteria;Gammaproteobacteria;Xanthomonadales;Xanthomonadaceae;Thermomonas;denitrifying Fe<II>-oxidizing bacterium
UGGCGGCAGGCCUAACACAUGCAAGUCGAACGGCAGCACAGCAGAGCUUGCUCUGUGGGUGGCGAGUGGCGGACGGGUGA
GGAAUACAUGGGAAUCUGCCCAGUCGUGGGGGAUAACGUAUGGAAACGUACGCUAAUACCGCAUGCGCCCUUUGGGGGAA
>cel-mir-46 MI0000017 Caenorhabditis elegans miR-46 stem-loop
CUGAGGUGAAGCUGAAGAGAGCCGUCUAUUGACAGUUCAAGACCACGAGUCGUUGUGUGC
GGUAUCAGGAAGUGGGCAACCGCCUCCAGACGCCGAGAAGCUGGUCAAACUUGGUCAUUUAGAGGAAGUAAAAGUCGUAA
CAAGGUUUCCGUAGGUGAACUGCGGA
