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: sum_quadratic.m
    path of file: ./repos/SGDLibrary/problem
    
    the code of the file until where you have to start completion: classdef sum_quadratic
%function [Problem] = sum_quadratic(A, b)
% This file defines sum quadratic problem class
%
% Inputs:
%           A(d:d:n)    n matrix of size dxd for n samples
%           b(d:n)      n column vectors of size d for n samples
%
% Output:
%       Problem     problem instance. 
%
%
% The problem of interest is defined as
%
%           min f(w) = 1/n * (sum_i^n 1/2 * w^T * A_i * w + b_i^T *
    
function [Problem] = sum_quadratic(A, b)
% This file defines sum quadratic problem class
%
% Inputs:
%           A(d:d:n)    n matrix of size dxd for n samples
%           b(d:n)      n column vectors of size d for n samples
%
% Output:
%       Problem     problem instance. 
%
%
% The problem of interest is defined as
%
%           min f(w) = 1/n * (sum_i^n 1/2 * w^T * A_i * w + b_i^T * w).
%           where 
%           w in R^d
%
% "w" is the model parameter of size d vector.
%
%
% This file is part of SGDLibrary.
%
% Created by H.Kasai on Mar. 13, 2017
% Modified by H.Kasai on Mar. 25, 2018


    properties
        name;    
        dim;
        samples;
        lambda;
        d;
        n;
        A;
        b;
        A_sum;
        b_sum;
        hessain_w_independ