public String generateMd5Sum() {
        for (String line : normalizedContent) {
            String s = normalize(line);
            if (!s.isEmpty()) {
                md5.update(toBytes(s));
            }
        }
        defMd5 = toHexString(md5.digest()).toLowerCase();
        //System.out.println("md5=" + defMd5) ;
        return defMd5;
    }
Normalizes a config definition line. Each string is normalized according to the
rules of config and definition files before they are used:
<ul>
<li>Remove trailing space.<li>
<li>Remove trailing comments, and spaces before trailing comments.</li>
<li>Remove empty lines</li>
<li>Keep comment lines</li>
</ul>
The supplied list is changed in-place

@param line a config definition line
@return a normalized config definition line
configgen/src/main/java/com/yahoo/config/codegen/NormalizedDefinition.java