code: def square(x):
      """Computes the square of `x` for additively secret-shared tensor `x`
  
      1. Obtain uniformly random sharings [r] and [r2] = [r * r]
      2. Additively hide [x] with appropriately sized [r]
      3. Open ([epsilon] = [x] - [r])
      4. Return z = [r2] + 2 * epsilon * [r] + epsilon ** 2
      """
      provider = crypten.mpc.get_default_provider()
      r, r2 = provider.square(x.size(), device=x.device)
  
      with IgnoreEncodings([x, r]):
          epsilon = (x - r).reveal()
      return r2 + 2 * r * epsilon + epsilon * epsilon
  
imports: import crypten
  import crypten.communicator
  import torch
  from crypten.common.util import count_wraps
  from crypten.config import cfg
label_desc: Use image node_id 8 for calling a global function with example usage: square(x) and returns: unknown