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: isreal.m
    path of file: ./repos/chebfun/@spherefun
    
    the code of the file until where you have to start completion: function varargout = isreal(varargin)
%ISREAL   Real-valued SPHEREFUN test.
%   ISREAL(F) returns logical true if F does not have an imaginary part and
%   false otherwise.
%  

    
function varargout = isreal(varargin)
%ISREAL   Real-valued SPHEREFUN test.
%   ISREAL(F) returns logical true if F does not have an imaginary part and
%   false otherwise.
%  
%   ~ISREAL(F) detects SPHEREFUN object that have an imaginary part even if it i
%   all zero.
%
%   Since only real-valued SPHEREFUNS are presently supported, this
%   function always returns a logical true.

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

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

end