@Override
        public boolean canBeReplaced(String id) {
            return this.id.equals(id);
        }
Merges a document into the source without moving it if it already exists.
If it does not yet exist in the source, merge it into the end. This is 
done with the submissive document.
tool-parent/tool-config/src/main/java/com/speedment/tool/config/util/DocumentMerger.java