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: Quadrature_Quadrilateral.m
    path of file: ./repos/Swan/FEM/Quadrature
    
    the code of the file until where you have to start completion: classdef Quadrature_Quadrilateral < Quadrature

    methods (Access = public)
        
        function computeQuadrature(obj,order)
            computeQuadrature@Quadrature(obj,order);
            switch order
                case 'CONSTANT'
                    obj.ngaus = 1;
                    obj.posgp(:,1) = [0,0];
                    obj.weigp = 4;
                    
                case 'LINEAR'
                    obj.ngaus = 4;
                    % Compute WEIGP and POSGP
                    a =  0.577350269189626;
                    obj.posgp(:,1) = [-a,-a];
                    obj.posgp(:,2) = [+a,-a];
                    obj.posgp(:,3) = [-a,+a];
                    obj.posgp(:,4) = [+a,+a];
                    
                    obj.weigp =  [1,1,1,1]';%1*ones(1,obj.ngaus);

                case 'QUADRATIC' %SERENDIPITY, QUADRILATERAL QUADRATIC NOT IMPLEMENTED
                    % Copied from down below
                    obj.ngaus = 9;
                    % Compute WEIGP and POSGP
                    a =  0.77459667;
                    obj.posgp(:,1) = [ 0,+a];
                    obj.posgp(:,2) = [ 0, 0];
                    obj.posgp(:,3) = [+a,+a];
                    obj.posgp(:,4) = [-a,-a];
                    obj.posgp(:,5) = [-a, 0];
                    obj.posgp(:,6) = [+a, 0];
                    obj.posgp(:,7) = [+a,-a];
                    obj.posgp(:,8) = [-a,+a];
                    obj.posgp(:,9) = [ 0,-a];
                    
                    obj.weigp =(4/9)*ones(1,obj.ngaus);

                case 'QUADRATICMSS' %SERENDIPITY, QUADRILATERAL QUADRATIC NOT IMPLEMENTED
                    obj.ngaus = 9;
                    % Compute WEIGP and POSGP
                    a =  0.77459667;
                    obj.posgp(:,1) = [ 0,+a];
                    obj.posgp(:,2) = [ 0, 0];
                    obj.posgp(:,3) = [+a,+a];
                    obj.posgp(:,4) = [-a,-a];
                    obj.posgp(:,5) = [-a, 0];
                    obj.posgp(:,6) = [+a, 0];
                    obj.posgp(:,7) = [+a,-a];
                    obj.posgp(:,8) = [-a,+a];
                    obj.posgp(:,9) = [ 0,-a];
                    
                    obj.weigp =(4/9)*ones(1,obj.ngaus);
                    
                case 'QUADRATICMASS'
                    posgl(1) =-0.774596669241483;
                    posgl(2) = 0.0;
                    posgl(3) = 0.774596669241483;
                    weigl(1) = 0.555555555555556;
                    weigl(2) = 0.888888888888889;
                    weigl(3) = 0.555555555555556;
                    obj.ngaus = 9;
                    igaus = 0;
                    
    
function computeQuadrature(obj,order)
            computeQuadrature@Quadrature(obj,order);
            switch order
                case 'CONSTANT'
                    obj.ngaus = 1;
                    obj.posgp(:,1) = [0,0];
                    obj.weigp = 4;
                    
                case 'LINEAR'
                    obj.ngaus = 4;
                    % Compute WEIGP and POSGP
                    a =  0.577350269189626;
                    obj.posgp(:,1) = [-a,-a];
                    obj.posgp(:,2) = [+a,-a];
                    obj.posgp(:,3) = [-a,+a];
                    obj.posgp(:,4) = [+a,+a];
                    
                    obj.weigp =  [1,1,1,1]';%1*ones(1,obj.ngaus);

                case 'QUADRATIC' %SERENDIPITY, QUADRILATERAL QUADRATIC NOT IMPLEMENTED
                    % Copied from down below
                    obj.ngaus = 9;
                    % Compute WEIGP and POSGP
                    a =  0.77459667;
                    obj.posgp(:,1) = [ 0,+a];
                    obj.posgp(:,2) = [ 0, 0];
                    obj.posgp(:,3) = [+a,+a];
                    obj.posgp(:,4) = [-a,-a];
                    obj.posgp(:,5) = [-a, 0];
                    obj.posgp(:,6) = [+a, 0];
                    obj.posgp(:,7) = [+a,-a];
                    obj.posgp(:,8) = [-a,+a];
                    obj.posgp(:,9) = [ 0,-a];
                    
                    obj.weigp =(4/9)*ones(1,obj.ngaus);

                case 'QUADRATICMSS' %SERENDIPITY, QUADRILATERAL QUADRATIC NOT IMPLEMENTED
                    obj.ngaus = 9;
                    % Compute WEIGP and POSGP
                    a =  0.77459667;
                    obj.posgp(:,1) = [ 0,+a];
                    obj.posgp(:,2) = [ 0, 0];
                    obj.posgp(:,3) = [+a,+a];
                    obj.posgp(:,4) = [-a,-a];
                    obj.posgp(:,5) = [-a, 0];
                    obj.posgp(:,6) = [+a, 0];
                    obj.posgp(:,7) = [+a,-a];
                    obj.posgp(:,8) = [-a,+a];
                    obj.posgp(:,9) = [ 0,-a];
                    
                    obj.weigp =(4/9)*ones(1,obj.ngaus);
                    
                case 'QUADRATICMASS'
                    posgl(1) =-0.774596669241483;
                    posgl(2) = 0.0;
                    posgl(3) = 0.774596669241483;
                    weigl(1) = 0.555555555555556;
                    weigl(2) = 0.888888888888889;
                    weigl(3) = 0.555555555555556;
                    obj.ngaus = 9;
                    igaus = 0;
                    nlocs = 3;
                    for ilocs = 1:nlocs
                        for jlocs = 1:nlocs
                            igaus = igaus+1;
                            obj.weigp(  igaus) = weigl(ilocs)*weigl(jlocs);
                            obj.posgp(1,igaus) = posgl(ilocs);
                            obj.posgp(2,igaus) = posgl(jlocs);
                        end