code: def _polyfit_typecast(x):
      if x.dtype.kind == "c":
          return x.astype(numpy.complex128, copy=False)
      return x.astype(numpy.float64, copy=False)
  
file_path: cupy/cupy/lib/_routines_poly.py
imports: import functools
  import warnings
  import numpy
  import cupy
  import cupyx.scipy.fft
label_desc: Use image node_id 8 for calling a global function with example usage: _polyfit_typecast(x) and returns: x, x