def extend(self, sequence):
    self.__field.validate(sequence)
    return list.extend(self, sequence)
the 4 neighboring positions
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/protorpc/protorpc/messages.py/FieldList.extend--crossover with--dataset/ETHPy150Open pybrain/pybrain/pybrain/rl/environments/twoplayergames/gomoku.py/GomokuGame._neighbors