code: def _multiply_complex_arr(X_fft):
      c = np.zeros(len(X_fft), dtype=np.complex128)
      for i, n in enumerate(X_fft):
          c[i] = n * (n.real + 1j * -n.imag)
      return c
  
imports: import math
  import numpy
  from sktime.utils.numba.njit import njit
label_desc: Use image node_id 5 for calling a global function with example usage: _multiply_complex_arr(X_fft) and returns: c