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: plus.m
    path of file: ./repos/chebfun/@deltafun
    
    the code of the file until where you have to start completion: function s = plus(f, g)
%+   Addition of DELTAFUN objects.
%   F + G adds F and G, where F and G may be DELTAFUN objects or scalars.
%
% Copyright 2017 by The University of Oxford and The Chebfun Developers. 
% See http://www.chebfun.org/ for Chebfun information.

%%

    
function s = plus(f, g)
%+   Addition of DELTAFUN objects.
%   F + G adds F and G, where F and G may be DELTAFUN objects or scalars.
%
% Copyright 2017 by The University of Oxford and The Chebfun Developers. 
% See http://www.chebfun.org/ for Chebfun information.

%%

% If one of the arguments is empty:
if ( isempty(f) || isempty(g) )
    % Return with an empty DELTAFUN:
    s = deltafun;
    return
end