@Override
  public String toString() {
    return "LoaderHelper region: " + getRegion() + " key: " + getKey() + " argument: "
        + getArgument();
  }
Return the argument object for the load method that was passed in from application code. This
object is passed in as <i>aLoaderArgument</i> in {@link Region#get(Object, Object) get}.

@return the argument or null if one was not supplied
geode-core/src/main/java/org/apache/geode/internal/cache/LoaderHelperImpl.java