code: def __setitem__(self, idx, val):
      # index of the leaf
      idx += self._capacity
      self._value[idx] = val
      idx //= 2
      while idx >= 1:
          self._value[idx] = self._operation(
              self._value[2 * idx], self._value[2 * idx + 1]
          )
          idx //= 2
  
imports: import argparse
  import operator
  import os
  import random
  import time
  import gym
  import matplotlib.pyplot
  import numpy
  import tensorflow
  import tensorlayer
label_desc: Use image node_id 4 for calling the SegmentTree obj's underlying member method code with example usage: obj.__setitem__(idx, val) without return types