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: iszero.m
    path of file: ./repos/chebfun/@spherefun
    
    the code of the file until where you have to start completion: function varargout = iszero(varargin)
%ISZERO   Check if a SPHEREFUN is identically zero on its domain.
%   OUT = ISZERO( F ) return 1 if the SPHEREFUN is exactly the zero function, and
%   0 otherwise. 

% Copyright 2017 by The University of Oxford and The Chebfun Developers.
% See http://www.chebfun.org/ for Chebfun information.

    
function varargout = iszero(varargin)
%ISZERO   Check if a SPHEREFUN is identically zero on its domain.
%   OUT = ISZERO( F ) return 1 if the SPHEREFUN is exactly the zero function, and
%   0 otherwise. 

% Copyright 2017 by The University of Oxford and The Chebfun Developers.
% See http://www.chebfun.org/ for Chebfun information.

[varargout{1:nargout}] = iszero@separableApprox(varargin{:});

end