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: build_figure.m
    path of file: ./repos/BrainStat/brainstat_matlab/plotting/volume_viewer/@volume_viewer/private
    
    the code of the file until where you have to start completion: %% Figure initialization. 
function varargout = build_figure(varargin)
% VIEWER MATLAB code for viewer.fig
%      VIEWER, by itself, creates a new VIEWER or raises the existing
%      singleton*.
%
%      H = VIEWER returns the handle to a new VI
    
function are returned to the command line.
% RV: This is the default generated by GUIDE. I haven't touched it.
function varargout = viewer_OutputFcn(hObject, eventdata, handles) 
% varargout  cell array for returning output args (see VARARGOUT);
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure
varargout{1} = handles.output;
end