}

        ResolutionGroup cached = cache.get(
                artifact,
                request.isResolveManagedVersions(),
                request.getLocalRepository(),
                request.getRemoteRepositories());

        if (cached != null
                // if the POM has no file, we cached a missing artifact, only return the cached data if no update forced

     */
    @Nullable
    Path getPath();

    /**
     * Creates a new byte stream to the source contents.
     * Closing the returned stream is the responsibility of the caller.
     *
     * @return a byte stream to the source contents, never {@code null}
     * @throws IOException in case of IO issue
     */
    @Nonnull
    InputStream openStream() throws IOException;

    /**

    /**
     * Interpolates expressions in the specified model. Note that implementations are free to either interpolate the
     * provided model directly or to create a clone of the model and interpolate the clone. Callers should always use
     * the returned model and must not rely on the input model being updated.
     *
     * @param model The model to interpolate, must not be {@code null}.

//
public interface RepositoryCache {

    /**
     * Puts the specified data into the cache. <strong>Warning:</strong> The cache will directly save the provided
     * reference. If the cached data is mutable, i.e. could be modified after being put into the cache, the caller is
     * responsible for creating a copy of the original data and store the copy in the cache.
     *

 *
 */
public interface Source {

    /**
     * Gets a byte stream to the source contents. Closing the returned stream is the responsibility of the caller.
     *
     * @return A byte stream to the source contents, never {@code null}.
     * @throws IOException in case of IO issue
     */
    InputStream getInputStream() throws IOException;

    /**

     * from any repository but are present among the set of specified projects will not cause an exception. Instead,
     * those unresolved artifacts will be returned in the result set, allowing the caller to take special care of
     * artifacts that haven't been build yet.
     *
     * @param projects The projects whose dependencies should be resolved, may be {@code null}.

     * @param columnNumber The one-based index of the column containing the error or {@code -1} if unknown.
     * @param exception The exception that caused this problem, may be {@code null}.
     */
    // mkleint: does this need to be public?
    public DefaultModelProblem(
            String message,
            Severity severity,
            Version version,

 *
 * @since 4.0.0
 */
@Experimental
public interface PathType {
    /**
     * The type for all paths that could not be placed in any of the types requested by a caller.
     * This type can appear in the return value of a call to
     * {@link Session#resolveDependencies resolveDependencies(...)} when at least one dependency
     * cannot be associated to any type specified in the {@code desiredTypes} argument.

FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED

        List<ToolchainPrivate> toRet = new ArrayList<>();

        ToolchainFactory fact = factories.get(type);
        if (fact == null) {
            logger.error("Missing toolchain factory for type: " + type + ". Possibly caused by misconfigured project.");
        } else {
            List<ToolchainModel> availableToolchains =
                    org.apache.maven.toolchain.model.ToolchainModel.toolchainModelToApiV4(