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/@classicfun
    
    the code of the file until where you have to start completion: function out = isreal(f)
%ISREAL   True for real CLASSICFUN.
%   ISREAL(F) returns TRUE if F does not have an imaginary part and FALSE
%   otherwise.

    
function out = isreal(f)
%ISREAL   True for real CLASSICFUN.
%   ISREAL(F) returns TRUE if F does not have an imaginary part and FALSE
%   otherwise.
%
% See also REAL, IMAG.

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

% Check if the ONEFUN of f is real:
out = isreal(f.onefun);

end