code: def rastrigin(x: np.ndarray) -> float:
      sum_cos = float(np.sum(np.cos(2 * np.pi * x)))
      return 10.0 * (x.size - sum_cos) + sphere(x)
  
imports: from typing import List, Callable, Optional
  from math import exp, sqrt
  import numpy
label_desc: Use image node_id 3 for calling a global function with example usage: rastrigin(x) and returns: unknown