@Override
  public String toString() {
    return "SnapshotOptionsImpl@" + System.identityHashCode(this) + ": "
        + "parallel=" + parallel + "; invokeCallbacks=" + invokeCallbacks
        + "; filter=" + filter + "; mapper=" + mapper;
  }
Returns the snapshot file mapper for parallel import and export.

@return the mapper
@see #setParallelMode(boolean)
geode-core/src/main/java/org/apache/geode/internal/cache/snapshot/SnapshotOptionsImpl.java