code: public void restoreAllMockVolume(final Collection<MockVolume> volumes) {
          allMockVolumes.clear();
          if (null != volumes) {
              for (MockVolume instance : volumes) {
                  allMockVolumes.put(instance.getVolumeId(), instance);
              }
          }
      }
docs: Clear {@link #allMockVolumes} and restore it from given a collection of instances.
  
  @param volumes
  collection of Volumes to restore