hi all:
org.apache.giraph.aggregators has these tow methods:

 void aggregate(A value)

  A   getAggregatedValue() 


Now I want to use  aggregate()  in vertex_program to send value of type A for global aggregating,  however,
I want the output of custom aggregator  is  type B .

that is to say ,  
void aggregate(A value)
  B   getAggregatedValue()

Is there any idea for this? 
Thank a lot !


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Luo