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: mne_mesh_edges.m
    path of file: ./repos/spm12/external/mne
    
    the code of the file until where you have to start completion: function [edges] = mne_mesh_edges(faces)

% MESH_EDGES   Returns sparse matrix with edges number
%
%   SYNTAX
%       [EDGES] = MESH_EDGES(FACES)
%
%   faces : matrix of size [n_trianges, 3]
%   edges : sparse matrix of size [n_vertices, n_vertices]

%
%   Author : Alexandre Gramfort, MGH Martinos Center
%   License : BSD 3-clause
%


    
function [edges] = mne_mesh_edges(faces)

% MESH_EDGES   Returns sparse matrix with edges number
%
%   SYNTAX
%       [EDGES] = MESH_EDGES(FACES)
%
%   faces : matrix of size [n_trianges, 3]
%   edges : sparse matrix of size [n_vertices, n_vertices]

%
%   Author : Alexandre Gramfort, MGH Martinos Center
%   License : BSD 3-clause
%

me = 'MESH_EDGES';

if nargin == 0
    eval(['help ',lower(me)])
    return
end