code: def cos(self):
      r"""Computes the cosine of the input using cos(x) = Re{exp(i * x)}
  
      Args:
          iterations (int): for approximating exp(i * x)
      """
      return cossin(self)[0]
  
imports: import math
  import torch
  from fate.arch.protocol import mpc
  from ..common.util import chebyshev_series
  from ..config import cfg
label_desc: Use image node_id 8 for calling a global function with example usage: cos() and returns: cossin