ImmutableMap.Builder<String, Integer> builder = new Builder<>();
    final StringHolder holder = new StringHolder();
    holder.string = "one";
    Entry<String, Integer> entry =
        new AbstractMapEntry<String, Integer>() {
          @Override
          public String getKey() {
            return holder.string;
          }

          @Override
          public Integer getValue() {

    }

    protected DefaultModelRepositoryHolder(DefaultModelRepositoryHolder holder) {
        this.session = holder.session;
        this.repositoryMerging = holder.repositoryMerging;
        this.pomRepositories = List.copyOf(holder.pomRepositories);
        this.externalRepositories = List.copyOf(holder.externalRepositories);
        this.repositories = List.copyOf(holder.repositories);
    }

    @Override

     *
     * @param session The session to use to resolve the model, must not be {@code null}.
     * @param parent The parent coordinates to resolve, must not be {@code null}.
     * @param modified a holder for the updated parent, must not be {@code null}.
     * @return The source of the requested POM, never {@code null}.
     * @throws ModelResolverException If the POM could not be resolved from any configured repository.
     */