public void registerScaleCallBack(String callBackName, Runnable callBack) {
    Preconditions.checkNotNull(callBackName, "callBackName");
    Preconditions.checkNotNull(callBack, "callBack");

    if (callBacks.containsKey(callBackName)) {
      throw new IllegalArgumentException("The callBackName " + callBackName +
          " is duplicated and has been registered already.");
    } else {
      callBacks.put(callBackName, callBack);
    }
  }
public void registerScaleCallBack(String callBackName, Runnable callBack) {
    Preconditions.checkNotNull(callBackName, "callBackName");
    Preconditions.checkNotNull(callBack, "callBack");

    if (callBacks.containsKey(callBackName)) {
      throw new IllegalArgumentException("The callBackName " + callBackName +
          " is duplicated and has been registered already.");
    } else {
      callBacks.put(callBackName, callBack);
    }
  }
public void registerScaleCallBack ( String callBackName , Runnable callBack ) { Preconditions . checkNotNull ( callBackName , "callBackName" ) ; Preconditions . checkNotNull ( callBack , "callBack" ) ; if ( callBacks . containsKey ( callBackName ) ) { throw new IllegalArgumentException ( "The callBackName " + callBackName + " is duplicated and has been registered already." ) ; } else { callBacks . put ( callBackName , callBack ) ; } }
Register callback and deduplicate it if any.
@param callBackName the name of callback. It should be identical.
@param callBack the callback passed in from upper layer, such as Hive.
Register callback and deduplicate it if any .