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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 plot_posterior_contour(self, idx_param1=0, idx_param2=1, res1=100, res2=100, smoothing=0.01):
 """ Plots a contour of the kernel density estimation of a 2D projection of the current posterior distribution. :param int idx_param1: Parameter to be treated as :math:`x` when plotting. :param int idx_param2: Parameter to be treated as :math:`y` when plotting. :param int res1: Resolution along the :math:`x` direction. :param int res2: Resolution along the :math:`y` direction. :param float smoothing: Standard deviation of the Gaussian kernel used to smooth the particle approximation to the current posterior. .. seealso:: :meth:`SMCUpdater.posterior_mesh` """

        return plt.contour(*self.posterior_mesh(idx_param1, idx_param2, res1, res2, smoothing))