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: xASL_adm_GetNumFromStr.m
    path of file: ./repos/ExploreASL/Functions/Administration
    
    the code of the file until where you have to start completion: function num = xASL_adm_GetNumFromStr(str)
%xASL_adm_GetNumFromStr Obtains single number from string. 
% CAVE there should only be one number!
%
% FORMAT:       num = xASL_adm_GetNumFromStr(str)
% 

    
function num = xASL_adm_GetNumFromStr(str)
%xASL_adm_GetNumFromStr Obtains single number from string. 
% CAVE there should only be one number!
%
% FORMAT:       num = xASL_adm_GetNumFromStr(str)
% 
% INPUT:        ...
%
% OUTPUT:       ...
% 
% -----------------------------------------------------------------------------------------------------------------------------------------------------
% DESCRIPTION:  Obtains single number from string. 
%               {{CAVE}} there should only be one number!
%
% -----------------------------------------------------------------------------------------------------------------------------------------------------
% EXAMPLE:      ...
% __________________________________
% Copyright 2015-2020 ExploreASL


    indices     = regexp(str,'\d');
    num         = str2num(str(indices(1):indices(end