code: def update(self, p, v):
      p += self.size
      self.tree[p] = v
      while p > 1:
          p = p // 2
          self.tree[p] = self.fn(self.tree[p * 2], self.tree[p * 2 + 1])
  
label_desc: Use image node_id 3 for calling the SegmentTree obj's underlying member method code with example usage: obj.update(p, v) without return types