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: test31.m
    path of file: ./repos/SuiteSparse/GraphBLAS/Test/unused
    
    the code of the file until where you have to start completion: function test31
%TEST31 test GrB_transpose

% SuiteSparse:GraphBLAS, Timothy A. Davis, (c) 2017-2023, All Rights Reserved.
% SPDX-License-Identifier: Apache-2.0

fprintf ('\n------------------- simple tests of GB_mex_transpose\n') ;

rng ('default') ;
A = sprand (4, 3, 0.4) ;
% full (A)
% full (A')
C = GB_mex_transpose (sparse (3,4), [ ], [ ], A) ;
assert (GB_spok (C.matrix) == 1) ;
assert (isequal (C.matrix,A')) ;

% C = A
D = struct ('inp0', 'tran') ;
C = GB_mex_transpose (sparse(4,3), [ ], [ ], A, D) ;
assert (isequal (C.matrix,A)) ;

% C = A'
C = GB_mex_transpose (sparse(3,4), [ ], [ ], A) ;
assert (isequal (C.matrix,A')) ;

Cin = sprand (4, 3, 0.5) ;
Cin2 = Cin' ;

% C = A'
C = GB_mex_transpose (Cin2, [ ], [ ], A) ;
assert (isequal (C.matrix,A')) ;

% C = Cin2+A'
C = GB_mex_transpose (Cin2, [ ], 'plus', A) ;
assert (isequal (C.matrix,Cin2+A')) ;

% C = Cin+A
D = struct ('inp0', 'tran') ;
C = GB_mex_transpose (Cin, [ ], 'plus', A, D) ;
assert (isequal (C.matrix,Cin+A)) ;

ops = {
    'first',
    'second',
    'pair',
    'oneb', % same as pair
    'min',
    'max',
    'plus',
    'minus',
    'times',
    'div',   } ;

for k = 1:length(ops)
    op = ops {k} ;

    % C = op (Cin2,A')
    D = struct ;
    C = GB_mex_transpose  (Cin2, [ ], op, A, D)  ;
    S = GB_spec_transpose (Cin2, [ ], op, A, D)  ;
    assert (isequal (C.matrix, sparse (S.matrix))) ;
    assert (isequal (GB_spones_mex (C.matrix), sparse (S.pattern))) ;

    % C = A', ignore the op
    D = struct ('outp', 'replace') ;

    
function test31
%TEST31 test GrB_transpose

% SuiteSparse:GraphBLAS, Timothy A. Davis, (c) 2017-2023, All Rights Reserved.
% SPDX-License-Identifier: Apache-2.0

fprintf ('\n------------------- simple tests of GB_mex_transpose\n') ;

rng ('default') ;
A = sprand (4, 3, 0.4) ;
% full (A)
% full (A')
C = GB_mex_transpose (sparse (3,4), [ ], [ ], A) ;
assert (GB_spok (C.matrix) == 1) ;
assert (isequal (C.matrix,A')) ;

% C = A
D = struct ('inp0', 'tran') ;
C = GB_mex_transpose (sparse(4,3), [ ], [ ], A, D) ;
assert (isequal (C.matrix,A)) ;

% C = A'
C = GB_mex_transpose (sparse(3,4), [ ], [ ], A) ;
assert (isequal (C.matrix,A')) ;

Cin = sprand (4, 3, 0.5) ;
Cin2 = Cin' ;

% C = A'
C = GB_mex_transpose (Cin2, [ ], [ ], A) ;
assert (isequal (C.matrix,A')) ;

% C = Cin2+A'
C = GB_mex_transpose (Cin2, [ ], 'plus', A) ;
assert (isequal (C.matrix,Cin2+A')) ;

% C = Cin+A
D = struct ('inp0', 'tran') ;
C = GB_mex_transpose (Cin, [ ], 'plus', A, D) ;
assert (isequal (C.matrix,Cin+A)) ;

ops = {
    'first',
    'second',
    'pair',
    'oneb', % same as pair
    'min',
    'max',
    'plus',
    'minus',
    'times',
    'div',   } ;

for k = 1:length(ops)
    op = ops {k} ;

    % C = op (Cin2,A')
    D = struct ;
    C = GB_mex_transpose  (Cin2, [ ], op, A, D)  ;
    S = GB_spec_transpose (Cin2, [ ], op, A, D)  ;
    assert (isequal (C.matrix, sparse (S.matrix))) ;
    assert (isequal (GB_spones_mex (C.matrix), sparse (S.pattern))) ;

    % C = A', ignore the op
    D = struct ('outp', 'replace') ;
    C = GB_mex_transpose  (Cin2, [ ], op, A, D) ;
    S = GB_spec_transpose (Cin2, [ ], op, A, D) ;
    assert (isequal (GB_spones_mex (C.matrix), sparse (S.pattern))) ;

    % C = A, ignore the op
    D = struct ('inp0', 'tran', 'outp', 'replace') ;
    C = GB_mex_transpose  (Cin, [ ], op, A, D) ;
    S = GB_spec_transpose (Cin, [ ], op, A, D) ;
    assert (isequal (GB_spones_mex (C.matrix), sparse (S.pattern))) ;

    % C = op (Cin,A)
    D = struct ('inp0', 'tran') ;
    C = GB_mex_transpose  (Cin, [ ], op, A, D) ;
    S = GB_spec_transpose (Cin, [ ], op, A, D) ;
    assert (isequal (GB_spones_mex (C.matrix), sparse (S.pattern))) ;

end