code: def fftfreq(n, d=1.0):
      """Return the FFT sample frequencies.
  
      Args:
          n (int): Window length.
          d (scalar): Sample spacing.
  
      Returns:
          cupy.ndarray: Array of length ``n`` containing the sample frequencies.
  
      .. seealso:: :func:`numpy.fft.fftfreq`
      """
      return cupy.hstack(
          (
              cupy.arange(0, (n - 1) // 2 + 1, dtype=np.float64),
              cupy.arange(-(n // 2), 0, dtype=np.float64),
          )
      ) / (n * d)
  
imports: import functools
  import math
  import numpy
  import cupy
  from cupy.fft import config
  from cupy.fft._cache import get_plan_cache
label_desc: Use image node_id 31 for calling a global function with example usage: fftfreq(n, d) and returns: unknown