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_nonlinSys2_C2.m
    path of file: ./repos/chebfun/tests/chebop
    
    the code of the file until where you have to start completion: function pass = test_nonlinSys2_C2(pref)
% Test 2x2 system (sin/cos). This is the same problem as test_nonlinSystem1,
% but using CHEBMATRIX {} syntax.
%
% Asgeir Birkisson, April 2014.

    
function pass = test_nonlinSys2_C2(pref)
% Test 2x2 system (sin/cos). This is the same problem as test_nonlinSystem1,
% but using CHEBMATRIX {} syntax.
%
% Asgeir Birkisson, April 2014.

if ( nargin == 0 )
    pref = cheboppref;
end