master.put(key, plugin);
                    }
                }

                Map<Object, List<Plugin>> predecessors = new LinkedHashMap<>();
                List<Plugin> pending = new ArrayList<>();
                for (Plugin element : tgt) {
                    Object key = getPluginKey().apply(element);
                    Plugin existing = master.get(key);

                return String.valueOf(QUALIFIERS.indexOf(""));
            }

            int i = QUALIFIERS.indexOf(qualifier);

            // Just returning an Integer with the index here is faster, but requires a lot of if/then/else to check for
            // -1
            //  or QUALIFIERS.size and then resort to lexical ordering. Most comparisons are decided by the first
            // character,

     * transformations on the remote repositories being used. For example if you replace existing repositories with
     * mirrors then it's easier to just replace the whole list with a new list of transformed repositories.
     *
     * @param repositories
     * @return This request, never {@code null}.
     */