final CollectStepData data = mock(CollectStepData.class);

        RequestTrace haveItFirst = RequestTrace.newChild(null, data)
                .newChild("foo")
                .newChild("bar")
                .newChild("baz");
        assertThat(ReverseTreeRepositoryListener.lookupCollectStepData(haveItFirst), sameInstance(data));

        RequestTrace haveItLast = RequestTrace.newChild(null, "foo")

/**
 * Caches raw plugin descriptors. A raw plugin descriptor is a descriptor that has just been extracted from the plugin
 * artifact and does not contain any runtime specific data. The cache must not be used for descriptors that hold runtime
 * data like the plugin realm. <strong>Warning:</strong> This is an internal utility interface that is only public for

        }
    }

    @Override
    public Optional<String> getString(URI relativeSource, Charset charset) {
        requireNonNull(charset, "charset is null");
        Optional<byte[]> data = getBytes(relativeSource);
        return data.map(bytes -> new String(bytes, charset));
    }

    @Override
    public void put(Path source, URI relativeTarget) {
        requireNonNull(source, "source is null");

    }

    @SuppressWarnings("unchecked")
    private ConcurrentMap<Key, PluginVersionResult> getCache(PluginVersionRequest request) {
        SessionData data = request.getRepositorySession().getData();
        return (ConcurrentMap<Key, PluginVersionResult>)
                data.computeIfAbsent(CACHE_KEY, () -> new ConcurrentHashMap<>(256));
    }

    private static Key getKey(PluginVersionRequest request) {

    @Nonnull
    public Type require(String id) {
        nonNull(id, "id");
        return usedTypes.computeIfAbsent(id, i -> {
            Type type = types.get(id);
            if (type == null) {
                // Copy data as the ArtifactHandler is not immutable, but Type should be.
                ArtifactHandler handler = manager.getArtifactHandler(id);
                type = new DefaultType(
                        id,

 * classloading capability - remote resolution of dependencies - do we want a model for sharing
 * information among plugins, is this more like an extension point - do we need a sort of bus for
 * application data - do we need a dictionary for our applications like Apple does. We could easily
 * hook into this and this is the model we need to follow - how many of our REST services do not map
 * directory to a method in the application interface?

                    }
                } else {
                    // System.out.println("+++>"+v.getMd().toDomainString()+" still has "+edge.toString() );
                    // fill in domain md with actual version data
                    ArtifactMetadata md = v.getMd();
                    ArtifactMetadata newMd = new ArtifactMetadata(
                            md.getGroupId(),
                            md.getArtifactId(),

SHALL THE APACHE SOFTWARE FOUNDATION OR * ITS CONTRIBUTORS BE LIABLE 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 OF THE...

DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE 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 OF THE POSSIBILITY...

NO EVENT SHALL THE AUTHORS, COPYRIGHT HOLDERS OR ITS CONTRIBUTORS BE LIABLE 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 OF THE POSSIBILITY...