You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: AbstractComplexHypersphericalDistribution.m
    path of file: ./repos/libDirectional/lib/distributions/complexHypersphere
    
    the code of the file until where you have to start completion: classdef (Abstract) AbstractComplexHypersphericalDistribution < AbstractDistribution
    % Abstract base class for distributions on the hypershere (Sd)
    
    methods
        function m = mean(~) %#ok<STOUT> 
            error('Mean currently not supported.')
     
    
function surfaceArea = computeUnitSphereSurface(dimension)
            % Computes surface area of (d-1)-sphere
            % see http://en.wikipedia.org/wiki/N-sphere#Volume_and_surface_area
            % dimension = 2 => circle
            % dimension = 3 => sphere
            % ...
            %
            % Parameters:
            %   dimension (scalar)
            %       the dimension of the sphere
            % Returns:
            %   surfaceArea (scalar)
            %       the surface area of the sphere
            surfaceArea = 2*pi^dimension / factorial(dimension-1);
        end