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: test_roots01.m
    path of file: ./repos/chebfun/tests/chebfun2v
    
    the code of the file until where you have to start completion: function pass = test_roots01( pref )

    
function pass = test_roots01( pref )
% Check that the marching squares and Bezoutian agree with each other. 
% Uncomment tests if harder tests should be executed.

if ( nargin < 1 ) 
    pref = chebfunpref; 
end