return checkNotNull(iterator);
  }

  /**
   * Returns an iterator over the merged contents of all given {@code iterators}, traversing every
   * element of the input iterators. Equivalent entries will not be de-duplicated.
   *
   * <p>Callers must ensure that the source {@code iterators} are in non-descending order as this
   * method does not sort its input.
   *

				// delete marker, if not add a new version for this delete
				// marker.
				if versioned {
					vr.VersionID = mustGetUUID()
				}
			}
		}
		// De-dup same object name to collect multiple versions for same object.
		v, ok := versionsMap[objects[i].ObjectName]
		if ok {
			v.Versions = append(v.Versions, vr)
		} else {
			v = FileInfoVersions{