docs: def increase(self, infile):
          '''Increase: 任意の箇所のバイト列と それより大きなサイズの任意のバイト列と入れ換える
          '''
          gf = infile[31:]
          index = gf.index(random.choice(gf))
          index_len = len(gf[index])
          large_size_index = random.choice([gf.index(g) for g in gf if len(g) > index_len])
          gf[index], gf[large_size_index] = gf[large_size_index], gf[index]
          return infile[:31] + gf