def _double_prefix(deque):
    new_len = max(len(deque[0]) * 2,
                  (len(deque[0]) + len(deque[1])))
    _merge_prefix(deque, new_len)
Resolve framer link
dataset/ETHPy150Open D-L/SimpleBookMarks/src/tornado/iostream.py/_double_prefix--crossover with--dataset/ETHPy150Open ioflo/ioflo/ioflo/base/framing.py/Frame.resolveFramerLink