code: def __init__(self, x):
      self._x = x
  
file_path: chainer/chainer/functions/math/zeta.py
imports: from chainer.backends import cuda
  from chainer import function_node
  from chainer import utils
  from chainer.utils import type_check
label_desc: Use image node_id 1 to create a new Zeta object from inherited base classes: function_node with example: obj = Zeta(x)