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: length.m
    path of file: ./repos/SuiteSparse/GraphBLAS/GraphBLAS/@GrB
    
    the code of the file until where you have to start completion: function n = length (G)
%LENGTH the length of a vector.
% length (G) is the length of the vector G.  For matrices, it is
% max (size (G)) if G is non-empty, or zero if G has any zero dimension.
% If any dimension of G exceeds flintmax, the result is returned as int64
% to avoid integer overflow.

    
function n = length (G)
%LENGTH the length of a vector.
% length (G) is the length of the vector G.  For matrices, it is
% max (size (G)) if G is non-empty, or zero if G has any zero dimension.
% If any dimension of G exceeds flintmax, the result is returned as int64
% to avoid integer overflow.
%
% See also GrB/size, GrB/numel.

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

G = G.opaque ;
[m, n] = gbsize (G) ;

if (m == 0 || n == 0)
    n = 0 ;
else
    n = max (m, n) ;
end