public static void registerNewAggregationFunction(String name,Class<? extends AggregationFunction> clazz,AggregationFunctionMetaDataProvider metaDataProvider){
  AGGREATION_FUNCTIONS.put(name,clazz);
  AGGREGATION_FUNCTIONS_META_DATA_PROVIDER.put(name,metaDataProvider);
}

public static void registerNewAggregationFunction ( String name , Class < ? extends AggregationFunction > clazz , AggregationFunctionMetaDataProvider metaDataProvider ) { AGGREATION_FUNCTIONS . put ( name , clazz ) ; AGGREGATION_FUNCTIONS_META_DATA_PROVIDER . put ( name , metaDataProvider ) ; }
with this method extensions might register additional aggregation functions if needed .
