3. Neither the name of the copyright holder nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
“AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS

    final Map<Path, Holder> modelByPath = new ConcurrentHashMap<>();

    final Map<GAKey, Holder> modelByGA = new ConcurrentHashMap<>();

    public static class Holder {
        private volatile boolean set;
        private volatile Model model;

        Holder() {}

        Holder(Model model) {
            this.model = Objects.requireNonNull(model);

    final Map<Path, Holder> modelByPath = new ConcurrentHashMap<>();

    final Map<GAKey, Holder> modelByGA = new ConcurrentHashMap<>();

    public static class Holder {
        private volatile boolean set;
        private volatile Model model;

        Holder() {}

        Holder(Model model) {
            this.model = Objects.requireNonNull(model);

    }

    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

                Model model = findRawModel(from, gId, aId);
                if (model != null) {
                    context.modelByGA.put(new GAKey(gId, aId), new Holder(model));
                    context.modelByPath.put(model.getPomPath(), new Holder(model));
                }
                return model;
            }

            @Override
            public Model getRawModel(Path from, Path path) {

                Model model = findRawModel(from, gId, aId);
                if (model != null) {
                    context.modelByGA.put(new GAKey(gId, aId), new Holder(model));
                    context.modelByPath.put(model.getPomFile(), new Holder(model));
                }
                return model;
            }

            @Override
            public Model getRawModel(Path from, Path path) {

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
“AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

     *
     * @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.
     */

 Copyright <YEAR> <COPYRIGHT HOLDER>

 Permission is hereby granted, free  of charge, to any person obtaining
 a  copy  of this  software  and  associated  documentation files  (the
 "Software"), to  deal in  the Software without  restriction, including
 without limitation  the rights to  use, copy, modify,  merge, publish,
 distribute,  sublicense, and/or sell  copies of  the Software,  and to
 permit persons to whom the Software  is furnished to do so, subject to

modification follow.

TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

0. This License applies to any program or other work which contains a
notice placed by the copyright holder saying it may be distributed under
the terms of this General Public License. The "Program", below, refers
to any such program or work, and a "work based on the Program" means