def __init__(self):
    self.items = []
    self.length = 0
    self.size = 0
The trajectory of the Environment
dataset/ETHPy150Open livid/v2ex/mapreduce/context.py/ItemList.__init__--crossover with--dataset/ETHPy150Open SmokinCaterpillar/pypet/pypet/environment.py/Environment.trajectory