human
Solve the following python programming problem given the following code:
def itilbert(x, h, period = None, _cache = _cache) : 
    '
    Return inverse h-Tilbert transform of a periodic sequence x.

    If ``x_j`` and ``y_j`` are Fourier coefficients of periodic functions x
    and y, respectively, then::

      y_j = -sqrt(-1)*tanh(j*h*2*pi/period) * x_j
      y_0 = 0

    For more details, see `tilbert`.

    ' 
    tmp = asarray (x) 
    if iscomplexobj (tmp) : 
        return (itilbert (tmp.real, h, period) + (1j * itilbert (tmp.imag, h, period))) 
if (period is not None) : 
        h = (((h * 2) * pi) / period) 
n = len (x) 
    omega = _cache.get ((n, h)) 
    if (omega is None) : 
        if (len (_cache) > 20) : 
            while _cache : 
                _cache.popitem () 
def kernel(k, h = h) : 
            if k : 
                return (- tanh ((h * k))) 
return 0 
omega = convolve.init_convolution_kernel (n, _cache, d = 1) 
        _cache [(n, h)] = omega 
overwrite_x = _datacopied (tmp, x) 
    return convolve.convolve (tmp, omega, swap_real_imag = 1, overwrite_x = overwrite_x) 

    
    

    Fix the buggy line: omega = convolve.init_convolution_kernel (n, _cache, d = 1)
assistant
#Here is Python program to fix the buggy line: omega = convolve.

omega = convolve.init_convolution_kernel (n, def kernel(, d = 1)