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: subsasgn.m
    path of file: ./repos/spm/@gifti
    
    the code of the file until where you have to start completion: function this = subsasgn(this, subs, A)
% Subscript assignment for GIfTI objects
%__________________________________________________________________________

% Guillaume Flandin
% Copyright (C) 2008-2023 Wellcome Centre for Human Neuroimaging

    
function this = subsasgn(this, subs, A)
% Subscript assignment for GIfTI objects
%__________________________________________________________________________

% Guillaume Flandin
% Copyright (C) 2008-2023 Wellcome Centre for Human Neuroimaging


switch subs(1).type
    case '.'
        if ~ismember(subs(1).subs, ...
                {'vertices' 'faces' 'normals' 'cdata','mat','indices','private'})
            error('Reference to non-existent field ''%s''.',subs(1).subs);
        end