*
   * <p>The multimap supports mapping removal, which removes the corresponding mapping from the map.
   * It does not support any operations which might add mappings, such as {@code put}, {@code
   * putAll} or {@code replaceValues}.
   *
   * <p>The returned multimap will be serializable if the specified map is serializable.
   *

                        Version.V20,
                        prefix + "layout",
                        repository.getId(),
                        "uses the unsupported value 'legacy', artifact resolution might fail.",
                        repository);
            }
        }
    }

    private void validate20RawResources(