public synchronized Collection<ContainerShutdownDescriptor> removeShutdownDescriptors(GavLabel gavLabel) {
        List<ContainerShutdownDescriptor> descriptors;
        if (gavLabel != null) {
            descriptors = removeFromPomLabelMap(gavLabel);
            removeFromPerContainerMap(descriptors);
        } else {
            // All entries are requested
            descriptors = new ArrayList<>(shutdownDescriptorPerContainerMap.values());
            clearAllMaps();
        }

        Collections.reverse(descriptors);
        return descriptors;
    }
Get all shutdown descriptors for a given pom label and remove it from the tracker. The descriptors
are returned in reverse order of their registration.

If no pom label is given, then all descriptors are returned.

@param gavLabel the label for which to get the descriptors or <code>null</code> for all descriptors
@return the descriptors for the given label or an empty collection
src/main/java/io/fabric8/maven/docker/service/ContainerTracker.java