def encode(self, strs):
        strs = map(lambda x: x.replace("\n", "\n\n")+"_\n_", strs)
        return reduce(lambda x, y: x+y, strs, "")
Encodes a list of strings to a single string.
dataset/ETHPy150Open algorhythms/LeetCode/271 Encode and Decode Strings.py/CodecMethod2.encode