docs: def rev_comp(dna):
          """
          Parameters
          ----------
          dna : bytearray
              dna sequence to be reverse complemented
          """
          
          i2 = len(dna) - 1
          
          l = len(dna) // 2
          
          for i in range(0, l):
              b = DNA_COMP_DICT[dna[i]]
              dna[i] = DNA_COMP_DICT[dna[i2]]
              dna[i2] = b
              i2 -= 1