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

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

% Double-well Schrodinger eigenstates
% Nick Trefethen, November 2010

% A well-known problem in quantum mechanics is the calculat
    
function V(x) defined on [-1,1] by
%
%    V(x) = 1.5 for x in [-.2,.3],  0 otherwise.
%
% We seek eigenmodes of the steady-state ShrÃ¶dinger equation associated
% with this potential, specifically, functions u(x) satisfying
%
%     -0.007u"(x) + V(x)*u(x) = lam*u(x),    u(-1) = u(1) = 0.
%
% for some constant lam. 

x = chebfun(@(x) x);
V = 1.5*(abs(x-0.05) < 0.25);
L = chebop(@(x,u) -0.007*diff(u,2) + V.*u, [-1, 1], 0);
e = eigs(L, 12, pref);

% Results from computation in Chebfun V4:
V4 = [  0.091480998228413
        0.116757122005510
        0.363909308597386
        0.463167687390724
        0.808941736699187
        1.021145960786674
        1.390812031498242
        1.652575851343383
        1.871230031210140
        2.174488704534987
        2.533176594994942
        2.924094539795185];
    
err = norm(V4 - e, inf);
pass = err < 1e-10;

end