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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def multitaper_cross_spectrum(self, clm, slm, k, convention='power', unit='per_l', **kwargs):
 """ Return the multitaper cross-spectrum estimate and standard error. Usage ----- mtse, sd = x.multitaper_cross_spectrum(clm, slm, k, [convention, unit, lmax, taper_wt, clat, clon, coord_degrees]) Returns ------- mtse : ndarray, shape (lmax-lwin+1) The localized multitaper cross-spectrum estimate, where lmax is the smaller of the two spherical-harmonic bandwidths of clm and slm, and lwin is the spherical-harmonic bandwidth of the localization windows. sd : ndarray, shape (lmax-lwin+1) The standard error of the localized multitaper cross-spectrum estimate. Parameters clm : SHCoeffs class instance SHCoeffs class instance containing the spherical harmonic coefficients of the first global field to analyze. slm : SHCoeffs class instance SHCoeffs class instance containing the spherical harmonic coefficients of the second global field to analyze. k : int The number of tapers to be utilized in performing the multitaper spectral analysis. convention : str, optional, default = 'power' The type of output spectra: 'power' for power spectra, and 'energy' for energy spectra. unit : str, optional, default = 'per_l' The units of the output spectra. If 'per_l', the spectra contain the total contribution for each spherical harmonic degree l. If 'per_lm', the spectra contain the average contribution for each coefficient at spherical harmonic degree l. lmax : int, optional, default = min(clm.lmax, slm.lmax) The maximum spherical-harmonic degree of the input coefficients to use. taper_wt : ndarray, optional, default = None The weights used in calculating the multitaper cross-spectral estimates and standard error. clat, clon : float, optional, default = 90., 0. Latitude and longitude of the center of the spherical-cap localization windows. coord_degrees : bool, optional, default = True True if clat and clon are in degrees. """

        return self._multitaper_cross_spectrum(clm, slm, k,
                                               convention=convention,
                                               unit=unit, **kwargs)