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: lengauer_tarjan_dominator_tree.m
    path of file: ./repos/CBIG/external_packages/matlab/default_packages/matlab_bgl_mac64
    
    the code of the file until where you have to start completion: function pred=lengauer_tarjan_dominator_tree(A,u,varargin)
% LENGAUER_TARJAN_DOMINATOR_TREE Compute a dominator tree for a graph.
%
% A dominator tree encodes dominates relations.  A vertex u dominates a
% vertex v if all paths to v must go through u.  In an undirected graph,
% this means that if u dominates v, then v will be disconnected from the
% graph if we remove u and start the search at the root.  A dominator tree
% is rooted at a particular vertex and the entire graph must be reachable
% from that vertex.  (Historically, these were called flowgraphs.)
%
% p = lengauer_tarjan_dominator_tree(A,u) returns the predecessor array for
% the dominator tree rooted at u.  
%
% The runtime is O((V+E) log (V+E)) and the algorithm works on unweighted,

    
function pred=lengauer_tarjan_dominator_tree(A,u,varargin)
% LENGAUER_TARJAN_DOMINATOR_TREE Compute a dominator tree for a graph.
%
% A dominator tree encodes dominates relations.  A vertex u dominates a
% vertex v if all paths to v must go through u.  In an undirected graph,
% this means that if u dominates v, then v will be disconnected from the
% graph if we remove u and start the search at the root.  A dominator tree
% is rooted at a particular vertex and the entire graph must be reachable
% from that vertex.  (Historically, these were called flowgraphs.)
%
% p = lengauer_tarjan_dominator_tree(A,u) returns the predecessor array for
% the dominator tree rooted at u.  
%
% The runtime is O((V+E) log (V+E)) and the algorithm works on unweighted,
% directed graphs.
%
% ... = lengauer_tarjan_dominator_tree(A,...) takes a set of
% key-value pairs or an options structure.  See set_matlab_bgl_options
% for the standard options. 
%   There are no additional options for this function.
%
% Note: this function does not depend