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: resolve_tag_block.m
    path of file: ./repos/Image-Harmonization-Dataset-iHarmony4/Lalonde and Efros/utils/mycode/xml/load_xml
    
    the code of the file until where you have to start completion: % A helper function for parsing xml.  Given a string containing 
    
function for parsing xml.  Given a string containing xml blocks
% and a tag name, find the first top-level block.
%
% Author: Joe Rollo
%
% Some code was taken from parseXMLelement.m
%
% Input: a string with xml tag blocks in the format <tag>text</tag>
% Each tag's text is allowed to contain child tags.
%
% Output: 
% -tagBlock a partition of the xml input into a substring containing a tag
% block, or an empty string if no tag blocks are found.
% -tagName the name of the first top-level tag block.  If the tag contains
% attributes, than this will also.
%
function [tagBlock, tagName] = resolve_tag_block(xml)

tagBlock = [];
tagName = '';

numChars = length(xml);

% Find the first tag.
jBegin  = strfind(xml, '<');

if isempty(jBegin)
    
    % No tags.
    return;
end