in maddpg/trainer/replay_buffer.py [0:0]
def add(self, obs_t, action, reward, obs_tp1, done):
data = (obs_t, action, reward, obs_tp1, done)
if self._next_idx >= len(self._storage):
self._storage.append(data)
else:
self._storage[self._next_idx] = data
self._next_idx = (self._next_idx + 1) % self._maxsize