code: def _pre_warp(wp, ws, analog):
      # Pre-warp frequencies for digital filter design
      if not analog:
          passb = cupy.tan(pi * wp / 2.0)
          stopb = cupy.tan(pi * ws / 2.0)
      else:
          passb = wp * 1.0
          stopb = ws * 1.0
      return passb, stopb
  
imports: import warnings
  import math
  from math import pi, prod
  import cupy
  from cupyx.scipy.special import binom
  import cupyx.scipy.special
  from cupyx.scipy.signal import _optimize
  from cupyx.scipy.signal._polyutils import roots, poly
  from cupyx.scipy.signal._lti_conversion import abcd_normalize
label_desc: Use image node_id 38 for calling a global function with example usage: _pre_warp(wp, ws, analog) and returns: passb,  stopb