Undefined function or variable biconnected_componens_mex

I've been trying to compile a program of yours that uses Matlab BGL.

Output argument "a" (and maybe others) not assigned during call to
"biconnected_components_mex".

Error in biconnected_components (line 57)
    [a ci] = biconnected_components_mex(A);

Error in biconncore (line 22)
[a,C] = biconnected_components(A);

Error in graphprep (line 46)
[data.bicore data.bicore_filter data.bicore_separated
data.bicore_components] ...

Error in nise (line 39)
[~,pdata] = graphprep(A); % A: input graph

The biconnected_components_mex file is not in the matlab bgl folder. I found a version online but it only includes one line and says the following.

function [a ci] = biconnected_components_mex(A)
%

% Returns a, a list of articulation points, and ci, which indicates the
% biconnected component index for each edge. If ci is not requested, it is
% not constructed.

Are the parts missing from this file? Or should I use the matlab version instead of the mex file?

Thank you in advance.